States in which nominees got less than 1/3 of the vote

This is kind of the flip side of this exercise. These are the states where major party nominees were beaten by their combined opposition by better than two-to-one. The states listed here, for any given nominee in any given election, would be a subset of the states listed for his or her opponent here. But this shows where major party nominees have been exceptionally weak, regardless of whether their principal opponent was particularly strong, and this reveals some interesting new things. (States in which the nominee got less than 1/4 of the vote are bolded.)

2020
Biden: Wyoming, West Virginia, North Dakota, Oklahoma, Idaho (22)
Trump: Vermont, Massachusetts, Maryland (24)

2016
Hillary Clinton: Wyoming, West Virginia, North Dakota, Utah, Idaho, Oklahoma, South Dakota, Kentucky (39)
Trump: Hawaii, Vermont, California, Massachusetts (73)

Hillary Clinton's 21.88% in that state is the worst of any major party nominee in a state since 1980. Conversely, the 73 electoral votes' worth of states in which Trump got less than 1/3 of the vote was the most of any major-party nominee since 1972, and the most of any winning nominee since 1924.

2012
Obama: Utah, Wyoming, Idaho, Oklahoma (20)
Romney: Hawaii, Vermont (7)

Obama got 24.75% in Utah.

2008
Obama: Wyoming (3)
McCain: Hawaii, Vermont (7)

Even though Oklahoma was McCain's best state, Wyoming was the only state in which Obama got less than 1/3 of the vote in in 2008.

2004
Kerry: Utah, Idaho, Wyoming, Nebraska (17)
Bush: --

Bush's worst state was Massachusetts, where he got 36.78%.

2000
Gore: Utah, Idaho, Alaska, Wyoming, North Dakota, Nebraska (23)
Bush: Rhode Island, Massachusetts (16)

1996
Clinton: Alaska, Utah (8)
Dole: Rhode Island, Massachusetts, New York, Maine, Vermont, Hawaii (60)

Interestingly, Wyoming, which would become George W. Bush's best state in the next election, isn't even on this list; Bill Clinton got 36.84% there. 

1992
Clinton: Utah, Idaho, Nebraska, Alaska, North Dakota (20)
HW Bush: Rhode Island, Massachusetts, Maine, Vermont, Minnesota, Washington, Oregon, California (105)

Bill Clinton got 24.65% in Utah.

1988
Dukakis: Utah (5)
HW Bush: --

George H. W. Bush's worst state was Rhode Island, where he got 43.93%.

1984
Mondale: Utah, Idaho, Wyoming, Nebraska, Alaska, Oklahoma, New Hampshire, Nevada, Arizona, Kansas (50)
Reagan: --

Mondale got 24.68% in Utah. Reagan's worst state was Minnesota, where he got 49.54%.

1980
Carter: Utah, Idaho, Nebraska, North Dakota, Alaska, Nevada, Wyoming, Arizona, New Hampshire, Colorado, South Dakota, Montana, Kansas (57)
Reagan: --

Carter got 20.57% in Utah; no major party nominee since has gone as low as this in any state. Reagan's worst state was Rhode Island, where he got 37.20%.

1976
Carter: --
Ford: Georgia (12)

Carter's worst state was Utah, where he got 33.65%.

1972
McGovern: Mississippi, Oklahoma, Georgia, Alabama, Idaho, Utah, Florida, South Carolina, Louisiana, North Carolina, Kansas, Nebraska, Tennessee, Virginia, Arizona, Wyoming, Arkansas, Texas ( > 100)
Nixon: --

Nixon's worst state was Massachusetts, where he got 45.23%. (By the way, I haven't been including DC, but even in this election, Nixon got less than 1/4 of the vote in DC.)

McGovern went below 1/3 of the vote in two states with at least 14 electoral votes: Florida (17) and Texas (26). In Mississippi, Oklahoma, and Georgia, he got 19.63%, 24.00%, and 24.65%, respectively. This is the most recently that any major party nominee got less than 1/5 of the vote in a state.

Of the states in which McGovern got less than 1/3 of the vote, six voted for Adlai Stevenson twice (Mississippi, Georgia, Alabama, South Carolina, North Carolina, and Arkansas). Two of these six had also voted for Lyndon Johnson. 1968 was the first time North Carolina had voted Republican since 1928, and 1972 was the first time Arkansas voted Republican since 1872 (since it had voted for George Wallace in 1968).

1968
Humphrey: Alabama, Mississippi, Georgia, Tennessee, Louisiana, North Carolina, South Carolina, Arkansas, Idaho, Florida, Nebraska, Oklahoma, Virginia (120)
Nixon: Mississippi, Alabama, Louisiana, Georgia, Arkansas, Rhode Island, Massachusetts (63)

This was the last election in which both major party nominees got less than 1/3 of the vote in some of the same states, but by a neat coincidence, all the states in which they both got less than 1/3 of the vote were Wallace states, so I just coloured those in yellow.

Every state in which either Humphrey or Nixon got less than 25% was a Wallace state, although Nixon got less than 25% in one state (Louisiana) where Humphrey did not (in Louisiana, Nixon got 23.47%, and Humphrey, 28.21%). Although it's hard to compare this with later elections, Nixon's 13.52% in Mississippi does stand as unrivalled by any later winning nominee in any state (or, in fact, by any major party nominee, winning or losing, in any state). Humphrey's worst state was Alabama, where he got 18.72%.

1964
Johnson: Mississippi (7)
Goldwater: Rhode Island, Hawaii, Massachusetts, Maine, New York, West Virginia, Connecticut, Michigan (105)

1964 is the last time that the Republican nominee got less than 25% of the vote in a state carried by the Democratic nominee. (In 1968, every state in which Nixon got less than 25% voted for Wallace.) Democrats have subsequently gotten less than 25% in states voting for the Republican nominee in 1972, 1980, 1984, 1992, 2012, and 2016. Goldwater's worst state was Rhode Island, where he got 19.13%--slightly worse than McGovern would do in Mississippi. However, Johnson got only 12.86% in Mississippi, making that the worst state-level showing for a winning nominee in any election since (including 1968). 

In Alabama, Johnson wasn't on the ballot (hence the different tint); unpledged Democratic electors, votes for whom seemed to be a proxy for voting for Johnson, got 30.55%. (Counties in Alabama that voted for unpledged Democratic electors are indicated as though they had simply voted Democratic by Wikipedia and the Crystal Ball database, which isn't the case for votes for unpledged Democratic electors in 1956 or 1960.) (If the votes for unpledged Democratic electors in Alabama are added to Johnson's total, he received 61.35% of the national vote, rather than 61.05%.)

In every other state, Johnson managed to get over 40%, or at least two of every five voters.

1960
Kennedy: --
Nixon: Mississippi, Louisiana (18)

Kennedy's worst state was also Mississippi (which voted for unpledged electors), where he got 36.34%. Nixon got 24.67% in Mississippi. However, Kennedy carried Louisiana, with a bare majority of 50.42%. This was the last time the Republican got less than a third of the vote in a state (including in a state carried by his Democratic opponent) while the Democrat did not. 

1956
Stevenson: Vermont, Maine (8)
Eisenhower: Mississippi, South Carolina, Georgia (28)

This was the last time that the Republican got less than 25% of the vote in a state carried by his Democratic opponent, and won the national election. (The reverse--a Democrat getting less than 25% of the vote in a state carried by his or her Republican opponent, and winning the national election--has gone on to happen in 1964, 1992, and 2012.)

This is also the fourth-to-last time to date that the Republican has gotten less than 25% in a state, under any circumstances (the only three occasions since being 1960, 1964, and 1968). Democrats have gotten less than 25% in a state, since this election, in 1964, 1968, 1972, 1980, 1984, 1992, 2012, and 2016.

1952
Stevenson: Vermont, North Dakota, Kansas, South Dakota, Nebraska (25)
Eisenhower: Georgia (12)

This was the last time until 1976 that neither nominee would go below 25% in any state.

1948
Truman: Mississippi, South Carolina, Louisiana (27)
Dewey: Mississippi, South Carolina, Louisiana, Georgia, Alabama, Arkansas, Texas, North Carolina (86)

Again, both nominees got less than a third of the vote in some of the same states (as in 1968), but, as in 1968, all those where both did so voted for a third party. (In Alabama, Truman was not on the ballot.) Dewey got 2.62% in Mississippi, easily unmatched by any subsequent major-party nominee in any state; this was the last of 15 consecutive elections, beginning in 1892, in which the Republican nominee consistently got less than 10% in at least one state in the South (but never outside the South; even in 1912, the only state in which Taft got less than 10% outside the South was California, but he was not on the ballot and was able to get only write-in votes in that state). Truman got 10.09% in Mississippi (again, as in 1960, it was both major party nominees' worst state). 

1944
Roosevelt: --
Dewey: South Carolina, Mississippi, Texas, Alabama, Georgia, Louisiana, Florida, Arkansas, North Carolina (104)

Roosevelt's worst state was Kansas, where he got 39.18%.

1940
Roosevelt: --
Willkie: Mississippi, South Carolina, Louisiana, Alabama, Georgia, Texas, Arkansas, North Carolina, Florida, Virginia, Tennessee 

Roosevelt's worst state was Kansas, where he got 42.40%. This was actually the election in which he got the highest vote share in his worst state. However, FDR's performance in his worst state would later be outdone by Nixon in 1972, Reagan in 1984, and even George H. W. Bush in 1988.

1936
Roosevelt: --
Landon: South Carolina, Mississippi, Louisiana, Texas, Georgia, Alabama, Arkansas, Florida, North Dakota, North Carolina, Arizona, Nevada, Montana, Virginia, Oregon, Utah, Washington, Wisconsin, Tennessee, Minnesota, California, Oklahoma, Idaho 

Roosevelt's worst state was Maine, where he got 41.52%.

1896, 1932, and 1936 (and 1912) were the only elections between 1860 and 1964 (or between 1868 and 1964, if Maryland is not considered a Southern state) in which the Republican got less than 1/3 of the vote in any state outside the South. 

1932
Roosevelt: --
Hoover: South Carolina, Mississippi, Louisiana, Georgia, Texas, Arkansas, Alabama, Florida, Oklahoma, North Dakota, North Carolina, Virginia, Arizona, Nevada, Wisconsin, Tennessee

Roosevelt's worst state was Vermont, where he got 41.08%.

1928
Smith: Kansas, Michigan, Maine, Washington, Vermont (42)
Hoover: South Carolina, Mississippi, Louisiana (29)

1924
Davis: Minnesota, North Dakota, Wisconsin, California, Washington, Michigan, South Dakota, Vermont, Wyoming, Idaho, Iowa, Pennsylvania, Montana, Maine, Nevada, Colorado, Illinois, Kansas, Ohio, Oregon, Massachusetts, New Jersey, Connecticut, New York, Nebraska, Utah
Coolidge: South Carolina, Mississippi, Georgia, Texas, Louisiana, Alabama, Florida, Arkansas, Virginia (102)

Davis got less than 1/3 of the vote nationally, so some of these are states he did better in than he did nationally. 

Davis got 6.80% in Minnesota; he also got less than 10% in North Dakota, Wisconsin, and California. This would be the last time that the Democratic nominee got less than 10% in any state.

1920
Cox: Wisconsin, North Dakota, Minnesota, South Dakota, Washington, Michigan, Vermont, California, Iowa, Illinois, New York, Pennsylvania, Massachusetts, New Jersey, Maine, Nebraska, Wyoming, Montana, Kansas, Rhode Island, Connecticut
Harding: South Carolina, Mississippi, Texas, Georgia, Louisiana, Florida, Alabama (81)

Cox got 16.17% in Wisconsin.

1916
Wilson: --
Hughes: South Carolina, Mississippi, Louisiana, Georgia, Texas, Florida, Alabama, Arkansas, Virginia, Oklahoma (112)

Wilson's worst state was Vermont, where he got 35.22%.

1912
Wilson: Vermont, Washington, Michigan, Minnesota, Idaho, Pennsylvania, Utah (84)

I didn't bother doing Taft; Taft exceeded 1/3 of the vote in only eight states.

Wilson got 24.43% in Vermont; this was the last time until 1948 that a winning Democrat got less than 25% in a state (and the last time until 1964 that a winning Democrat got less than 25% in a state carried by the Republican).

Three of these states (Washington, Idaho, and Utah) voted for Wilson in 1916. (Idaho voted for Wilson in 1912; this was one of only two times when a candidate carried a state despite getting less than 1/3 of the vote in it, the other being Lincoln in California in 1860.)

1908
Bryan: Vermont, Washington, Michigan, California, Minnesota, Maine (50)
Taft: South Carolina, Mississippi, Louisiana, Florida, Texas, Alabama, Georgia (75)

This was the last time until 2016 that a winning nominee would get less than 1/3 of the vote in states worth more electoral votes than those Trump got less than 1/3 of the vote in in 2016, without his opponent getting less than 1/3 of the vote in even more electoral votes' worth of states.

Bryan got 21.82% in Vermont.

1904
Parker: Minnesota, Vermont, Washington, Oregon, North Dakota, South Dakota, Nebraska, Idaho, Michigan, Kansas, California, Pennsylvania, Wisconsin, Maine, Wyoming, Illinois, Iowa, Utah, Nevada
Roosevelt: South Carolina, Mississippi, Louisiana, Georgia, Alabama, Florida, Texas (75)

Parker got 18.84% in Minnesota.

1900
Bryan: Vermont (4)
McKinley: South Carolina, Mississippi, Florida, Louisiana, Georgia, Texas (58)

Bryan got 22.86% in Vermont.

1896
Bryan: Vermont, New Hampshire, Massachusetts, Rhode Island, Maine, Connecticut (39)
McKinley: Mississippi, South Carolina, Colorado, Utah, Nevada, Montana, Idaho, Louisiana, Florida, Arkansas, Alabama, Texas (80)

This was the second-to-last time until 2016 that a winning nominee would get less than 1/3 of the vote in states worth more electoral votes than those Trump got less than 1/3 of the vote in in 2016, without his opponent getting less than 1/3 of the vote in even more electoral votes' worth of states. (And in fact, the number of electoral votes represented by the states McKinley and Bryan got less than 1/3 of the vote in, respectively, were very similar to the number of electoral votes represented by the states Trump and Hillary Clinton got less than 1/3 of the vote in in 2016, respectively.)

Bryan got 16.66% in Vermont.

1892
Cleveland: Nevada, Nebraska, South Dakota, Oregon, Vermont (27)
Harrison: Mississippi, Alabama, South Carolina, Texas, Georgia, Louisiana, Nevada, Arkansas 

As in 1964, the more darkly-tinted states are states in which the respective nominees were not on the ballot. Nevada, the one state in which both major nominees got less than 1/3 of the vote, voted for Weaver, and so is in yellow.

Cleveland got 6.56% in Nevada. It was the only state in which he got less than 10%, but it made him the last Democrat until 1924 to get less than 10% in a state, and the last Democrat, to date, to get less than 10% in a state and win the national election.

1888
Cleveland: Vermont, Kansas (13)
Harrison: South Carolina, Texas, Mississippi, Louisiana, Georgia, Alabama (61)

Cleveland got 25.65% in Vermont. Harrison got 17.17% in South Carolina; this would be the last time until 1952 in which the Republican got at least 10% in every state.

1884
Cleveland: Vermont (4)
Blaine: South Carolina, Texas (22)

Cleveland got 29.18% in Vermont. Blaine got 23.41% in South Carolina.

1880
Hancock: Vermont, Kansas, Nebraska, Iowa (24)
Garfield: Texas, Mississippi (16)

Hancock got 28.09% in Vermont; Garfield got 23.95% in Texas.

1876
Tilden: Kansas, Vermont (10)
Hayes: Georgia, Texas, Mississippi (27)

Tilden got 30.53% in Kansas; Hayes got 27.97% in Georgia.

1872
Greeley: Vermont, South Carolina, Rhode Island, Nebraska, Massachusetts, Maine, Kansas
Grant: --

Grant's worst state was Texas, where he got 40.71%. No major party nominee would do as well as this in his or her worst state until 1932.

Greeley got 20.62% in Vermont.

1868
Seymour: Vermont, Massachusetts, Kansas, Tennessee
Grant: Kentucky, Louisiana, Maryland (25)

Seymour got 21.43% in Vermont.

1864
McClellan: Kansas, Vermont, Massachusetts, Missouri, West Virginia
Lincoln: Kentucky (11)

McClellan got 17.78% in Kansas.

1860 was a very complex election that doesn't lend itself well to this. In calculating past elections' 'Electoral College edge', Nate Silver began with 1864. In both 1860 and 1856, one of the two 'major' nominees was not on the ballot in a large number of states, and in both elections (but especially 1860), it wasn't even altogether clear that there were only two 'major' nominees. The elections from 1836 through 1852 follow a more normal pattern, but perhaps they are not of much interest. It might be worth noting in passing simply that in 1840 and 1844, neither of the major nominees got less than 1/3 of the vote in any state. In 1836, William Henry Harrison got 24.99% in New Hampshire; in 1848, Lewis Cass got 22.85% in Vermont, 25.07% in New York, 26.18% in Massachusetts, and 32.68% in Rhode Island, and Taylor got 29.50% in New Hampshire and 29.71% in Texas; and in 1852, Scott got 26.60% in Georgia, 26.93% in Texas, and 30.64% in New Hampshire, and Pierce got 29.72% in Vermont. These were the only instances in these five elections of a major nominee getting below 1/3 of the vote, and as you can see, in only two cases (New Hampshire in 1836 and Vermont in 1848) did a major party do any worse than 1/4 of the vote in any state. In 1840, Harrison got 43.37% in his worst state (Missouri), which would stand until 1972 as the best percentage a nominee was getting in his or her worst state. (van Buren's 40.07% in Vermont in 1836 was not far behind, although Grant did manage to best this in 1872.) In 1856--relatively suddenly--Buchanan (the winner) got 20.84% in Vermont, 23.08% in Massachusetts, and 32.84% in New York. The period from 1836 through 1852 actually seems to have been relatively un-polarised.

---

On election night 2004, George Mitchell said:

Well I think you have to [?] recognise that you can't win by being a regional party. The Democratic Party reached its peak in the past century when Franklin Roosevelt put together a coalition that spanned the entire country. And I think what we're lacking now is any kind of a reasonable base in large parts of the country, as you see on this big map behind us here. I think you have to be a national party to compete in national elections.

 

How weak parties are in their worst states may be a reasonable indicator of their health as a 'national party'. A nominee getting over 40% (or 2/5) of the vote in his worst state is strongly correlated with winning the national election--every nominee who has gotten over 40% in his worst state has won the election, in all but one case (van Buren in 1836) easily. A nominee getting over 2/3 of the vote in their worst state is fairly well correlated with winning the national election; only two nominees who have gotten over 1/3 of the vote in their worst state have lost, and they were both running against someone else who was also getting over 1/3 of the vote in their worst state (and, well, one of them had to lose) (but, in this case, there have been a number of close calls, such as Wilson in 1916, Kennedy in 1960, Carter in 1976, and Bush in 2004). These are the nominees who got over 1/3 of the vote in their worst states, first in order of when they ran (with the ones who got over 2/5 in bold):

Martin van Buren, 1836: Vermont (40.07%)
William Henry Harrison, 1840: Missouri (43.37%)
Martin van Buren, 1840: Vermont (35.47%) (lost)
James Polk, 1844: Vermont (36.96%)
Henry Clay, 1844: New Hampshire (36.32%) (lost)
Ulysses Grant, 1872: Texas (40.71%)
Woodrow Wilson, 1916: Vermont (35.22%)
Franklin Roosevelt, 1932: Vermont (41.08%)
Franklin Roosevelt, 1936: Maine (41.52%)
Franklin Roosevelt, 1940: Kansas (42.40%)
Franklin Roosevelt, 1944: Kansas (39.18%)
John Kennedy, 1960: Mississippi (36.34%)
Richard Nixon, 1972: Massachusetts (45.23%)
Jimmy Carter, 1976: Utah (33.65%)
Ronald Reagan, 1980: Rhode Island (37.20%)
Ronald Reagan, 1984: Minnesota (49.54%)
George H. W. Bush, 1988: Rhode Island (43.93%)
George W. Bush, 2004: Massachusetts (36.78%)

And then in order of the magnitude of their worst vote share:

Ronald Reagan, 1984: Minnesota (49.54%)
Richard Nixon, 1972: Massachusetts (45.23%)
George H. W. Bush, 1988: Rhode Island (43.93%)
William Henry Harrison, 1840: Missouri (43.37%)
Franklin Roosevelt, 1940: Kansas (42.40%)
Franklin Roosevelt, 1936: Maine (41.52%)
Franklin Roosevelt, 1932: Vermont (41.08%)
Ulysses Grant, 1872: Texas (40.71%)
Martin van Buren, 1836: Vermont (40.07%)
Franklin Roosevelt, 1944: Kansas (39.18%)
Ronald Reagan, 1980: Rhode Island (37.20%)
James Polk, 1844: Vermont (36.96%)
George W. Bush, 2004: Massachusetts (36.78%)
John Kennedy, 1960: Mississippi (36.34%)
Henry Clay, 1844: New Hampshire (36.32%) (lost)
Martin van Buren, 1840: Vermont (35.47%) (lost)
Woodrow Wilson, 1916: Vermont (35.22%)
Jimmy Carter, 1976: Utah (33.65%)  

To George Mitchell's point, there have been six elections in which a major nominee got at least 2/5 of the vote in every state in the 20th century. Three of them were 1932, 1936, and 1940, and the nominee doing so was Franklin Roosevelt. The other three were 1972, 1984, and 1988, and the nominee doing so was the Republican. 

Now, because of the nearly unanimous grip that the Democracy had on most of the Deep South and much of the Upper South from the 1880s through the 1950s, there is not quite as good a correlation between getting below a certain vote share in one's worst state and losing the national election. That said, the Democracy was never quite as shut out of a region as the GOP was out of the Deep South from the 1880s through the 1950s, and we can see when Democratic nominees got below 1/4 of the vote in his or her worst state:

Jackson, 1828: Massachusetts (17.78%)
Jackson, 1832: Massachusetts (20.61%)
Cass, 1848: Vermont (22.85%) (lost)
Buchanan, 1856: Vermont (20.84%)
Douglas, 1860: Vermont (19.41%) (lost)*
McClellan, 1864: Kansas (17.78%) (lost)
Seymour, 1868: Vermont (21.43%) (lost)
Greeley, 1872: Vermont (20.62%) (lost)
Cleveland, 1892: Nevada (6.56%)
Bryan, 1896: Vermont (16.66%) (lost)
Bryan, 1900: Vermont (22.86%) (lost)
Parker, 1904: Minnesota (18.84%) (lost)
Bryan, 1908: Vermont (21.82%) (lost)
Wilson, 1912: Vermont (24.43%)
Cox, 1920: Wisconsin (16.17%) (lost)
Davis, 1924: Minnesota (6.80%) (lost)
Truman, 1948: Mississippi (10.09%)
Johnson, 1964: Mississippi (12.86%)
Humphrey, 1968: Alabama (18.72%) (lost)
McGovern, 1972: Mississippi (19.63%) (lost)
Carter, 1980: Utah (20.57%) (lost)
Mondale, 1984: Utah (24.68%) (lost)
Clinton, 1992: Utah (24.65%)
Obama, 2012: Utah (24.75%)
Hillary Clinton, 2016: Wyoming (21.88%) (lost)

* 1860 was a complicated election, and Vermont was not actually Douglas' worst state. However, it was his worst state that Lincoln won, and if you add his and Breckenridge's vote shares in the state, the total of their two vote shares is still under 25%. (This is also the case in Massachusetts.)

So there have been 25 times the Democratic nominee got under 1/4 of the vote in his or her worst state, and on only nine of these occasions did the Democrat win (1828, 1832, 1856, 1892, 1912, 1948, 1964, 1992, and 2012). That's a minority, although not a tiny minority. Of course, many of these elections had an odd character. Of the nine Democratic winners, all save the three most recent (Johnson in 1964, Clinton in 1992, and Obama in 2012) were nevertheless doing better in their worst state than their Republican opponent was doing in theirs. Clinton was the first Democrat to win while getting less than 1/4 in a state while his Republican opponent did not go below 1/4 in any state. Obama in 2012 was the first Democrat to win while doing this in an election in which the two-party vote was over 94%.

We could also say that 1960 was the last in a string of consecutive elections going back to the 1800s in which the Republican got less than 1/3 of the vote in a former Confederate state that was carried by the Democrat, and just look at elections from 1964 on. (Since 1960, Republicans have gone below 1/3 of the vote in a former Confederate state only in 1976--although Barry Goldwater did go below 1/3 of the vote in West Virginia, which goes to show that even the South is not a monolith.) If we use 1/4 of the vote as a benchmark, it won't be very interesting, as the only Republicans to go below 1/4 of the vote in a state from 1964 on have been Goldwater in 1964 and Nixon in 1968 (which in and of itself is interesting). These are the nominees to have gotten below 1/3 of the vote in their worst state from 1960 on: 

Johnson, 1964: Mississippi (12.86%)
Goldwater, 1964: Rhode Island (19.13%) (lost)
Nixon, 1968: Mississippi (13.52%)
Humphrey, 1968: Alabama (18.72%) (lost)
McGovern, 1972: Mississippi (19.63%) (lost)
Ford, 1976: Georgia (32.96%) (lost)
Carter, 1980: Utah (20.57%) (lost)
Mondale, 1984: Utah (24.68%) (lost)
Dukakis, 1988: Utah (32.05%) (lost)
Clinton, 1992: Utah (24.65%)
HW Bush, 1992: Rhode Island (29.02%) (lost)
Clinton, 1996: Alaska (33.27%)
Dole, 1996: Rhode Island (26.82%) (lost)
Bush, 2000: Rhode Island (31.91%)
Gore, 2000: Utah (26.34%) (lost)
Kerry, 2004: Utah (26.00%) (lost)
Obama, 2008: Wyoming (32.54%)
McCain, 2008: Hawaii (26.58%) (lost)
Obama, 2012: Utah (24.75%)
Romney, 2012: Hawaii (27.84%) (lost)
Trump, 2016: Hawaii (30.03%)
Hillary Clinton, 2016: Wyoming (21.88%) (lost)
Biden, 2020: Wyoming (26.55%)
Trump, 2020: Vermont (30.67%) (lost)

24 major-party nominees, from 1964 through 2020, have gotten less than 1/3 of the vote in their worst state. Of those 24, nine won--a non-trivial, but distinct, minority of 37.5%. Of those nine, three were Republicans: Nixon in 1968, Bush in 2000, and Trump in 2016. The other six were Democrats. (Of all 24, 14--again, a majority, albeit not an overwhelming one, of 58.3%--were Democrats.)

Now, of all nine of these winning nominees, Johnson in 1964, Nixon in 1968, Clinton in 1992, Clinton in 1996, Bush in 2000, Obama in 2008, Obama in 2012, Trump in 2016, and Biden in 2020--were running in elections in which both major-party nominees were getting less than 1/3 of the vote in their worst state. Of the last eight elections, seven were ones in which both major-party nominees got less than 1/3 of the vote in their worst state. So the overall Republican superiority in terms of the proportion of major-party nominees from 1964 on who have gotten less than 1/3 of the vote in their worst state is primarily built upon elections between 1960 and 1992, and is likely to keep shrinking. 

So to figure out which party has the edge in terms of being closer to having a 'reasonable base' everywhere in the country, we have to get more subtle. Of course, it can be pointed out that, since 1968, Republicans have never gone below 1/4 of the vote in any state, whereas Democrats have done so in 1972, 1980, 1984, 1992, 2012, and 2016. However, if we begin with 1992--the first election of the present supposed era of Democratic dominance--that's only thrice (one of them in a three-way election). And in 2020, Biden managed to get over 1/4 of the vote in every state. Not only that, but his percentage in Wyoming was the best of any Democrat's in his or her worst state this century, apart from only Obama in 2008. So it seems that--possibly, at least--those three occasions of Democrats getting less than 1/4 of the vote in a state will remain relatively isolated occasions (rather than 2012 and 2016 representing the prelude to a regular occurrence). 

Well, it is in the last six elections that both parties seem to show regular weakness in some parts of the country (apart from the GOP in 2004). We can order all the past twelve major-party nominees' vote shares in their worst states, from best to worst:

Bush, 2004: Massachusetts (36.78%)
Obama, 2008: Wyoming (32.54%)
Bush, 2000: Rhode Island (31.91%)
Trump, 2020: Vermont (30.67%)
Trump, 2016: Hawaii (30.03%)
Romney, 2012: Hawaii (27.84%)
McCain, 2008: Hawaii (26.58%)
Biden, 2020: Wyoming (26.55%)
Gore, 2000: Utah (26.34%)
Kerry, 2004: Utah (26.00%)
Obama, 2012: Utah (24.75%)
Hillary Clinton, 2016: Wyoming (21.88%)

And, just in case anything is an outlier, we can do likewise with the past twelve major-party nominees' vote shares in their second-worst states:

Bush, 2004: Rhode Island (38.67%)
Obama, 2008: Oklahoma (34.35%)
Bush, 2000: Massachusetts (32.50%)
Trump, 2020: Massachusetts (32.14%)
Romney, 2012: Vermont (30.97%)
McCain, 2008: Vermont (30.45%)
Trump, 2016: Vermont (30.27%)
Biden, 2020: West Virginia (29.69%)
Kerry, 2004: Wyoming (29.07%)
Obama, 2012: Wyoming (27.82%)
Gore, 2000: Idaho (27.64%)
Hillary Clinton, 2016: West Virginia (26.43%)

The order doesn't change much. A few key things, in particular, are the same on both lists:

-Bush '04's vote share is the highest overall. 

-Aside from Obama '08, all the Democrats are below all the Republicans.

-Biden '20 is ahead of all the other Democrats save Obama '08 (again, possibly indicating that Democrats getting less than 1/4 of the vote in a state is not going to become a regular or even frequent occurrence). He is, however, still behind all the Republicans, including McCain '08.

-Trump '20 is the highest Republican aside from Bush '04 and Bush '00 on both lists. (So, if there had been a trend of Republicans getting equally weak in certain parts of the country as Democrats were, it didn't accelerate under Trump, but rather, if anything, slightly reversed, if not fully back to the Bush years.) On the first list, at least, Trump '16 is also ahead of both Romney and McCain (showing that it would be fallacious to attribute Hillary Clinton's bottom-scraping performances in her worst states to the supposedly enormous third-party vote in 2016). 

One other thing it's worth noting is that Massachusetts is the largest state mentioned here; it had 12 electoral votes in 2000 and 2004, and 11 in 2020. The next-largest of any of these states is one that Democrats did badly in: Oklahoma, which had 7 electoral votes in 2008. None of these states was a 'large' state (i.e., one with 14 or more electoral votes at the time of the election).

What if we used a finer proportion than 1/4 or 1/3? You might notice that, just from the above, we can see forthwith that Republicans got less than 30% of the vote in a state only twice this century: McCain in Hawaii in 2008 and Romney in Hawaii in 2012. Democrats, on the other hand, have done so at least ten times. Of course, '30%' feels artificial, an artefact of our having ten fingers. However, as we move through the whole numbers, '10' is the first one which, as a denominator, gives us a figure that is between 25% and 33.3%. (For example, 1/6 is 16.6%, and 3/8 is 37.5%.)

(OK, 2/7 is actually 28.571428%. Somehow, 7 doesn't seem to count in this context, although I'm not a mathematician. 1/10 is at least half of 1/5. But we can use 2/7 too--it won't make any difference. [2/9, which for some reason also doesn't seem to count [I guess it's 2/3 of 1/3], by the way, is 22.2%.])

So, in the last six elections, we can say that the only nominees who got below 3/10 (or 1.5/5) of the vote in at least one state have been:

Al Gore, 2000: Utah (26.34%)
John Kerry, 2004: Utah (26.00%)
John McCain, 2008: Hawaii (26.58%)
Barack Obama, 2012: Utah (24.75%)
Mitt Romney, 2012: Hawaii (27.84%)
Hillary Clinton, 2016: Wyoming (21.88%)
Joe Biden, 2020: Wyoming (26.55%)

(As you can see, they also all got below 2/7 of the vote in at least one state, although Romney came close to not doing so.)

Furthermore, in the past six elections, there is only one state that any Republican has gotten below 1.5/5 of the vote in: Hawaii. Democrats have done so in a number of states, and not just the two listed above: Gore got below 30% of the vote in four states; Kerry, in two states; Obama in '12, in two states; Hillary Clinton, in six states; and Biden, in two states. In all, Democrats have gone below 1.5/5 of the vote at least once in seven states this century, as opposed to Republicans doing so in one.

(If we use 2/7, this is a little different; Gore got less than 2/7 of the vote in the same four states; but Kerry did so in only one. Somewhat surprisingly--and this is why it might have seemed that Democrats were on a path of more consistently getting below certain percentages of the vote in at least one state--Obama in 2012 got less than 2/7 of the vote in two states, one more than Kerry. Hillary Clinton got less than 2/7 of the vote in five states, and Biden, in only one state. And no Democrat has ever done so, this century, in Oklahoma.)

Now, of course, one might say that it would be folly to say that the Republican Party in the age of Theodore Roosevelt, Warren Harding, and Dwight Eisenhower was not a 'national party' because it was regularly getting a few scores of votes in South Carolina and Mississippi (a--slight--exaggeration; Harding got 130.5 scores of votes in South Carolina). And that likewise, this doesn't indicate anything about the Democracy not being a healthy national party today. 

But the Solid South was a very idiosyncratic feature of the landscape of US politics. There's nothing akin to the War of Sections to explain why the various states in which Democrats are exceptionally weak, are exceptionally weak. The exceptional nature of the persistent extreme Republican weakness in the Solid South is further demonstrated if we list all 32 national presidential majorities ever won, bolding those that failed to stay above 1/4 of the vote in every state:

Lyndon Johnson, 1964 (61.05%)
Franklin Roosevelt, 1936 (60.80%)
Richard Nixon, 1972 (60.67%)
Warren Harding, 1920 (60.32%)
Ronald Reagan, 1984 (58.77%)
Herbert Hoover, 1928 (58.21%)
Franklin Roosevelt, 1932 (57.41%)
Dwight Eisenhower, 1956 (57.37%)
Theodore Roosevelt, 1904 (56.42%)
Andrew Jackson, 1828 (55.97%)
Ulysses Grant, 1872 (55.63%)
Dwight Eisenhower, 1952 (55.18%)
Abraham Lincoln, 1864 (55.02%)
Franklin Roosevelt, 1940 (54.74%)
Andrew Jackson, 1832 (54.23%)
Calvin Coolidge, 1924 (54.04%)
Franklin Roosevelt, 1944 (53.39%)
George H. W. Bush, 1988 (53.37%)
Barack Obama, 2008 (52.93%)
William Henry Harrison, 1840 (52.88%)
Ulysses Grant, 1868 (52.66%)
William McKinley, 1900 (51.64%)
William Howard Taft, 1908 (51.57%)
Joe Biden, 2020 (51.31%)
Barack Obama, 2012 (51.06%)
William McKinley, 1896 (51.03%)
Samuel Tilden, 1876 (50.92%)
Franklin Pierce, 1852 (50.84%)
Martin van Buren, 1836 (50.83%)
Ronald Reagan, 1980 (50.75%)
George W. Bush, 2004 (50.73%)
Jimmy Carter, 1976 (50.08%)

In general, one would expect that those winning a national majority would be less likely to go below 1/4 in any state, and this is true: of the above 32 nominees, only 12 went below 1/4 in any state.

That, however, is where the above table stops making sense. One would further expect that the higher a nominee's share of the national vote, the less likely it is that he or she will be getting less than 1/4 of the vote in any state. However, the nominees who were held to under 1/4 of the vote in at least one state are scattered relatively haphazardly across the table. If anything, they seem weighted towards the top. Of the top ten nominees, six were held to under 1/4 of the vote in at least one state. On the other hand, the bottom six--or all those who got between 50% and 51% of the vote--all managed to stay above 1/4 of the vote in every state. 

Nor is there a correlation with party--most of the particularly high vote-getters who fell below 1/4 in a state were Republicans, but several Republicans winning relatively small majorities also managed to stay above 1/4 in every state (Bush in '04, Reagan in '80, HW Bush in '88). 

However, the picture changes if we discount those Republican nominees in the above table between 1896 and 1956 (inclusive), who stayed above 1/4 of the vote in every state outside the South (1896 being the first Republican majority since Reconstruction):

Lyndon Johnson, 1964 (61.05%)
Franklin Roosevelt, 1936 (60.80%)
Richard Nixon, 1972 (60.67%)
Ronald Reagan, 1984 (58.77%)
Franklin Roosevelt, 1932 (57.41%)
Andrew Jackson, 1828 (55.97%)
Ulysses Grant, 1872 (55.63%)
Abraham Lincoln, 1864 (55.02%)
Franklin Roosevelt, 1940 (54.74%)
Andrew Jackson, 1832 (54.23%)
Franklin Roosevelt, 1944 (53.39%)
George H. W. Bush, 1988 (53.37%)
Barack Obama, 2008 (52.93%)
William Henry Harrison, 1840 (52.88%)
Ulysses Grant, 1868 (52.66%)
Joe Biden, 2020 (51.31%)
Barack Obama, 2012 (51.06%)
William McKinley, 1896 (51.03%)
Samuel Tilden, 1876 (50.92%)
Franklin Pierce, 1852 (50.84%)
Martin van Buren, 1836 (50.83%)
Ronald Reagan, 1980 (50.75%)
George W. Bush, 2004 (50.73%)
Jimmy Carter, 1976 (50.08%)

(McKinley in 1896 got below 1/4 of the vote in several Mountain West states; he remains the only Republican who won a majority of the national vote to have gotten less than 1/4 of the vote in a state outside the South.)

This table makes a lot more sense. The distribution of the nominees who fell below 1/4 of the vote in a state is still not entirely intuitive, although it is less top-loaded than it was before. More importantly, of 24 remaining nominees, only five got below 1/4 of the vote in any state--a much smaller proportion (20.83%) than before we removed the Republican nominees between 1896 and 1956 who won a national majority and stayed above 1/4 everywhere outside the South (37.5%). The top-performing ever nominee, Lyndon Johnson in 1964, is still one of those nominees who failed to stay above 1/4 in every state. Other than him, however, only one other nominee who got over 55.5% (or 55%) of the national vote also failed to stay above 1/4 in every state (as opposed to six such nominees on the unamended table)--Andrew Jackson in 1828. For just the two elections of 1828 and 1832, New England (or much of it) seemed almost as resistant to the Democracy as the Solid South would come to be to the GOP after Reconstruction, but this didn't last beyond the elections in which Jackson himself was on the ballot.

What this would seem to indicate is that, in general, regions of the country move with the country, such that nominees winning national majorities are likely to be staying above 1/4 of the vote in every state (and this likelihood increases with the nominee's vote share). The exception is the South (or much of it, anyway) between Reconstruction and the 1950s. And a party can hardly be faulted for not being a healthy national party for failing to win over a region of the country that simply refuses to move with the nation (especially if, despite failing to do so, it wins a number of national majorities and even landslides).

In any case, in the Solid South era, a kind of a proxy for when the Republicans were a healthy national party is when Democrats were getting less than 1/4 of the vote in their worst state: never between 1872 and 1892, but then in eight of nine elections from 1892 through 1924. (Democrats won four of five national popular votes from 1876 through 1892.) Conversely--as already discussed--Republicans haven't gone below 1/4 of the vote in any state since 1968.