Never-Democratic and never-Republican counties as of the past 16 elections

In the wake of the last couple of posts, I was left curious about how many never-Democratic and never-Republican counties there were after each election in the last several decades. 

After 2020 election

Never-Republican: 3 (Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 23 (Edwards, IL; Ogle, IL; Doniphan, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Poquoson City, VA; Grant, WV)

After 2016 election

Never-Republican: 3 (Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 24 (Edwards, IL; Ogle, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Poquoson City, VA; Grant, WV)

After 2012 election

Never-Republican: 4 (Elliott, KY; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 24 (Edwards, IL; Ogle, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Poquoson City, VA; Grant, WV)

After 2008 election

Never-Republican: 4 (Elliott, KY; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 24 (Edwards, IL; Ogle, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Poquoson City, VA; Grant, WV)

After 2004 election

Never-Republican: 7 (Elliott, KY; Floyd, KY; Knott, KY; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 27 (Broomfield, CO; Carroll, IL; Edwards, IL; Ogle, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Manassas City, VA; Poquoson City, VA; Grant, WV) 

After 2000 election

Never-Republican: 7 (Elliott, KY; Floyd, KY; Knott, KY; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 26 (Carroll, IL; Edwards, IL; Ogle, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Manassas City, VA; Poquoson City, VA; Grant, WV) 

After 1996 election

Never-Republican: 10 (Greenlee, AZ; Elliott, KY; Floyd, KY; Knott, KY; Morgan, KY; Wolfe, KY; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 26 (Carroll, IL; Edwards, IL; Ogle, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Manassas City, VA; Poquoson City, VA; Grant, WV)

After 1992 election

Never-Republican: 10 (Greenlee, AZ; Elliott, KY; Floyd, KY; Knott, KY; Morgan, KY; Wolfe, KY; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 28 (Carroll, IL; Edwards, IL; Ogle, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Colonial Heights City, VA; Emporia City, VA; Manassas City, VA; Poquoson City, VA; South Boston City, VA; Grant, WV)

After 1988 election

Never-Republican: 10 (Greenlee, AZ; Elliott, KY; Floyd, KY; Knott, KY; Morgan, KY; Wolfe, KY; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 31 (La Paz, AZ; Carroll, IL; Edwards, IL; Ogle, IL; Whiteside, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; Colonial Heights City, VA; Emporia City, VA; Manassas City, VA; Poquoson City, VA; South Boston City, VA; Grant, WV) 

After 1984 election

Never-Republican: 10 (Greenlee, AZ; Elliott, KY; Floyd, KY; Knott, KY; Morgan, KY; Wolfe, KY; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 32 (La Paz, AZ; Carroll, IL; Edwards, IL; Ogle, IL; Whiteside, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Cibola, NM; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; Colonial Heights City, VA; Emporia City, VA; Manassas City, VA; Poquoson City, VA; South Boston City, VA; Grant, WV)

After 1980 election

Never-Republican: 12 (Greenlee, AZ; Carroll, KY; Elliott, KY; Floyd, KY; Knott, KY; Morgan, KY; Wolfe, KY; Monroe, MO; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 30 (Carroll, IL; Edwards, IL; Ogle, IL; Whiteside, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; Colonial Heights City, VA; Emporia City, VA; Manassas City, VA; Poquoson City, VA; South Boston City, VA; Grant, WV) 

After 1976 election

Never-Republican: 13 (Greenlee, AZ; Carroll, KY; Elliott, KY; Floyd, KY; Knott, KY; Morgan, KY; Wolfe, KY; Monroe, MO; Stewart, TN; Brooks, TX; Jim Hogg, TX; Manassas Park City, VA; Menominee, WI)
Never-Democratic: 31 (Carroll, IL; Edwards, IL; Ogle, IL; Whiteside, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; Colonial Heights City, VA; Emporia City, VA; Lexington City, VA; Manassas City, VA; Poquoson City, VA; South Boston City, VA; Grant, WV)

After 1972 election

Never-Republican: 12 (Greenlee, AZ; Carroll, KY; Elliott, KY; Floyd, KY; Knott, KY; Morgan, KY; Wolfe, KY; Monroe, MO; Stewart, TN; Brooks, TX; Jim Hogg, TX; Menominee, WI)
Never-Democratic: 31 (Carroll, IL; Edwards, IL; Ogle, IL; Whiteside, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; Bedford City, VA; Colonial Heights City, VA; Emporia City, VA; Lexington City, VA; Salem City, VA; South Boston City, VA; Grant, WV) 

After 1968 election

Never-Republican: 137 (Greenlee, AZ; [Bradley, Calhoun, Cleburne, Cleveland, Cross, Dallas, Faulkner, Grant, Greene, Izard, Lawrence, Lonoke, Miller, Poinsett, Saline, Sevier, White, AR]; [Bradford, Gilchrist, Hamilton, Levy, Union, FL]; [Franklin, Hall, Hancock, Hart, Heard, Henry, Jackson, Madison, Rabun, Stephens, Treutlen, Troup, Upson, Ware, Wheeler, GA]; Oahu, HI; [Ballard, Calloway, Carlisle, Carroll, Elliott, Floyd, Franklin, Graves, Harrison, Henry, Hopkins, Knott, Meade, Morgan, Owen, Simpson, Trimble, Union, Webster, Wolfe, KY]; Cameron, LA; Mississippi, MO; Monroe, MO; [Currituck, Duplin, Gates, Hoke, Lee, Scotland, NC]; [Bryan, Choctaw, Johnston, Love, McCurtain, OK]; Cherokee, SC; Union, SC; [Cheatham, Coffee, Franklin, Gibson, Hardeman, Humphreys, Lake, Lauderdale, Lincoln, Marshall, Moore, Obion, Robertson, Stewart, Tipton, Trousdale, Williamson, Wilson, TN]; [Archer, Baylor, Bowie, Brooks, Burleson, Caldwell, Coke, Coryell, Crane, Delta, Fannin, Foard, Franklin, Freestone, Gonzales, Hardin, Haskell, Henderson, Hopkins, Jim Hogg, Kaufman, Leon, Limestone, Llano, Milam, Morris, Navarro, Newton, Orange, Rains, Rockwall, Sabine, San Saba, Shelby, Stonewall, Titus, Trinity, Van Zandt, Williamson, TX]; Chesapeake City, VA; Franklin, VA; Nelson, VA; Webster, WV, Menominee, WI)
Never-Democratic: 31 (Carroll, IL; Edwards, IL; Ogle, IL; Whiteside, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; Bedford City, VA; Colonial Heights City, VA; Emporia City, VA; Lexington City, VA; Salem City, VA; South Boston City, VA; Grant, WV) 

After 1964 election

Never-Republican: 149 (Greenlee, AZ; [Bradley, Calhoun, Cleburne, Cleveland, Cross, Dallas, Faulkner, Grant, Greene, Izard, Lawrence, Lonoke, Miller, Poinsett, Saline, Sevier, White, AR]; [Bradford, Gilchrist, Hamilton, Levy, Union, FL]; [Franklin, Hall, Hancock, Hart, Heard, Henry, Jackson, Madison, Rabun, Stephens, Treutlen, Troup, Upson, Ware, Wheeler, GA]; Oahu, HI; [Ballard, Calloway, Carlisle, Carroll, Elliott, Floyd, Franklin, Graves, Harrison, Henry, Hopkins, Knott, Meade, Morgan, Owen, Simpson, Trimble, Union, Webster, Wolfe, KY]; Cameron, LA; [Callaway, Maries, Mississippi, Monroe, Platte, MO];  [Currituck, Duplin, Gates, Hoke, Lee, Scotland, Union, NC]; [Bryan, Choctaw, Johnston, Love, McCurtain, Marshall, OK]; [Cherokee, Dillon, Spartanburg, Union, SC]; [Cheatham, Coffee, Franklin, Gibson, Hardeman, Humphreys, Lake, Lauderdale, Lincoln, Marshall, Moore, Obion, Putnam, Robertson, Stewart, Tipton, Trousdale, Williamson, Wilson, TN]; [Archer, Baylor, Bowie, Brooks, Burleson, Caldwell, Coke, Coryell, Crane, Delta, Fannin, Foard, Franklin, Freestone, Gonzales, Hardin, Haskell, Henderson, Hopkins, Jim Hogg, Kaufman, Leon, Limestone, Llano, Milam, Morris, Navarro, Newton, Orange, Rains, Rockwall, Sabine, San Saba, Shelby, Stonewall, Titus, Trinity, Van Zandt, Williamson, TX]; [Amherst, Chesapeake City, Craig, Fairfax City, Franklin, Franklin City, Nelson, VA]; Webster, WV, Menominee, WI)
Never-Democratic: 27 (Carroll, IL; Edwards, IL; Ogle, IL; Whiteside, IL; Doniphan, KS; Riley, KS; Jackson, KY; Leslie, KY; McCreary, KY; Garrett, MD; Missaukee, MI; Avery, NC; Wilkes, NC; Yadkin, NC; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; Colonial Heights City, VA; South Boston City, VA; Grant, WV) 

After 1960 election

Never-Republican: 261 ([Bibb, Choctaw, Coffee, Covington, Crenshaw, Dale, Henry, Lamar, Monroe, Pickens, Pike, Tallapoosa, Tuscaloosa, AL]; Greenlee, AZ; [Bradley, Calhoun, Cleburne, Cleveland, Columbia, Cross, Dallas, Faulkner, Grant, Greene, Howard, Izard, Lawrence, Lonoke, Miller, Poinsett, Saline, Sevier, White, AR]; [Bay, Bradford, Franklin, Gilchrist, Gulf, Hamilton, Lafayette, Levy, Liberty, Suwannee, Taylor, Union, Wakulla, FL]; [Atkinson, Bacon, Baker, Barrow, Berrien, Bleckley, Brantley, Brooks, Bulloch, Candler, Carroll, Clinch, Cobb, Crawford, Crisp, Dade, DeKalb, Dodge, Dooly, Early, Echols, Emanuel, Evans, Floyd, Franklin, Glascock, Grady, Gwinnett, Hall, Hancock, Hart, Heard, Henry, Irwin, Jackson, Jenkins, Lamar, Lanier, Laurens, Lincoln, Madison, Miller, Monroe, Montgomery, Oglethorpe, Peach, Pulaski, Rabun, Randolph, Schley, Seminole, Stephens, Stewart, Telfair, Terrell, Tift, Toombs, Treutlen, Troup, Turner, Upson, Walton, Ware, Wayne, Webster, Wheeler, Wilcox, Wilkes, Wilkinson, GA]; Oahu, HI; [Ballard, Calloway, Carlisle, Carroll, Elliott, Floyd, Franklin, Graves, Harrison, Henry, Hopkins, Knott, Meade, Morgan, Owen, Simpson, Trimble, Union, Webster, Wolfe, KY]; [Cameron, Franklin, Livingston, Richland, St Helena, Washington, West Carroll, LA]; [Alcorn, Benton, Calhoun, Choctaw, Covington, Franklin, Greene, Harrison, Itawamba, Jackson, Jasper, Jones, Leake, Lee, Neshoba, Newton, Perry, Pontotoc, Prentiss, Scott, Simpson, Smith, Tate, Tippah, Tishomingo, Union, Webster, Winston, Yalobusha, MS]; [Callaway, Maries, Mississippi, Monroe, Platte, MO];  [Currituck, Duplin, Gates, Hoke, Lee, Scotland, Union, NC]; [Bryan, Choctaw, Johnston, Love, McCurtain, Marshall, OK]; [Cherokee, Dillon, Florence, Greenwood, McCormick, Saluda, Spartanburg, Union, SC]; [Cheatham, Coffee, Franklin, Gibson, Hardeman, Humphreys, Lake, Lauderdale, Lincoln, Marshall, Moore, Obion, Putnam, Robertson, Stewart, Tipton, Trousdale, Williamson, Wilson, TN]; [Archer, Baylor, Bowie, Brooks, Burleson, Caldwell, Coke, Coryell, Crane, Delta, Fannin, Foard, Franklin, Freestone, Gonzales, Hardin, Haskell, Henderson, Hopkins, Jim Hogg, Kaufman, Leon, Limestone, Llano, Milam, Morris, Navarro, Newton, Orange, Rains, Rockwall, Sabine, San Saba, Shelby, Stonewall, Titus, Trinity, Van Zandt, Williamson, TX]; [Amherst, Craig, Franklin, Nelson, VA]; Webster, WV)
Never-Democratic: 75 (Hawaii, HI; Kauai, HI; Maui, HI; Carroll, IL; Edwards, IL; Mercer, IL; Ogle, IL; Whiteside, IL; Wabash, IN; Doniphan, KS; Douglas, KS; Riley, KS; Jackson, KY; Knox, KY; Leslie, KY; McCreary, KY; Whitley, KY; Garrett, MD; [Barnstable, Dukes, Franklin, Plymouth, MA]; [Antrim, Benzie, Charlevoix, Mecosta, Midland, Missaukee, Osceola, Tuscola, MI]; Ocean, NJ; [Chautauqua, Cortland, Essex, Genesee, Livingston, Ontario, Orleans, Schuyler, Washington, Wyoming, NY]; Avery, NC; Wilkes, NC; Yadkin, NC; [Clinton, Geauga, Meigs, Warren, OH]; Butler, PA; Cameron, PA; Forest, PA; Indiana, PA; Union, PA; Blount, TN; Carter, TN; Cocke, TN; Grainger, TN; Jefferson, TN; Johnson, TN; Sevier, TN; Unicoi, TN; Union, TN; [Addison, Bennington, Caledonia, Orange, Orleans, Rutland, Windham, Windsor, VT]; Colonial Heights City, VA; Galax City, VA; Norton City, VA; South Boston City, VA; Grant, WV)

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I should note that I caught a few discrepancies in earlier posts in the process of doing this, so it's possible there were others. 

I also counted every county and county-equivalent that had never voted for a given party, no matter how trivial. (For example, after the 1960 election, every county in Hawaii is counted as either 'never-Democratic' or 'never-Republican'.) I chose this option rather than choose some arbitrary number of elections in a row the county had to have voted against a given party. (Technically, Carter did carry a county that had never voted Democratic in his failed 1980 re-election bid, contrary to what I mentioned here; he carried the independent city of Lexington, Virginia, which had voted Republican in 1968, 1972, and 1976--its first three participating elections. Likewise contrary to what I said there, Reagan did carry a never-Republican county-equivalent in his initial election in 1980--the independent city of Manassas Park, Virginia, which had voted for Carter in its first participating election in 1976.)

At the moment, of course, the Republicans have a fairly large lead in terms of the number of counties that have never voted for the opposition party: 23 vs. 3. One thing I was wondering was if this had always been the case. Well, it has been the case in every election from 1972 on, but not before. On the eve of both the 1972 and 1968 elections, the never-Republican counties outnumbered the never-Democratic counties by several times. 

Now, I felt compelled to do this for the eve of the 1964 election (or for after the 1960 election), because that was an election that could reverse the situation again: perhaps there were so many theretofore never-Democratic counties that LBJ carried in 1964 that, on the eve of the 1964 election, the never-Democratic and never-Republican counties were relatively evenly matched. 

Well, even taking into account the possibility of errors and miscounting on my part, even on the eve of the 1964 election, the never-Republican counties substantially outnumbered the never-Democratic counties. If I am anything like correct, there were more than thrice as many never-Republican as never-Democratic counties on Halloween, 1964. 

I could have extended this back one more election, to 1960, without too much trouble, at least prima facie, because I happen to already have the counties Nixon carried in 1960 that had never voted Republican before (they are listed here; there were 11 15). However, constant changes in the statuses of Virginia's independent cities, and the statehood of Hawaii, and the possibility of other idiosyncrasies, meant it didn't happen. Regardless, it seems safe to say that the Democratic lead in counties that had never voted for the other party existed on the eve of the 1960 election as well (and would only have been greater before the 1956 and 1952 Eisenhower landslides). The Republican Party might have led before the FDR landslides--that, I'm not hardy enough to do.

I was surprised at the large lead the Democracy had in counties that had never voted for the other party. Perhaps I shouldn't have been surprised that the Democracy led in this respect as of the 1972 election (and perhaps I wouldn't have been if I had thought about it some). But I was surprised that the Democracy led in this respect--and at the extent of the Democracy's lead--as of even the 1964 election.

A few other interesting things that this brings to light:

In 1964, Goldwater flipped never-Republican counties, if I am not mistaken, in only these states. This was the same set of states as those Southern states in which there were no never-Democratic counties left by 1912, less Delaware, Texas, and Virginia. 

In a similar vein, if I am not mistaken, the only Southern state in which Johnson carried a never-Democratic county in 1964 was Kentucky (I am disregarding Virginia's independent cities here). Those counties that had been hardy enough to reject the Democracy continuously since their founding in Tennessee, West Virginia, North Carolina, and Maryland resisted Johnson (as did most of those in Kentucky--Whitley County voted for Johnson by three votes out of over 9,500 cast), illustrating the greater determination of Jacksonian Republicans to stick by party than their co-partisans in the Northeast or Midwest. (In both Pennsylvania and Michigan, a number of never-Democratic counties existed as of Halloween 1964, but the ensuing election left only one surviving such county in each.)

The sheer number of counties that had never voted for one or the other of the two major parties was qualitatively bigger for both parties up until the 1964 election, and remained so for the Republican Party up until the 1972 election, than it is today, making it not really all that surprising that a presidential nominee would not carry a county that had never voted for his or her party before. Even though the number of never-Democratic counties today seems large compared to the number of never-Republican counties today, it is fewer than a third as many never-Democratic counties as there were on Halloween, 1964. 

1964 and 1972 seem to have been the last elections that were really able to shake loose large numbers of counties that had never voted for one of the two parties before (in 1964, this was the case of both parties). There weren't that many never-Republican counties left by Halloween, 1984, but nevertheless, it's interesting how paltry Reagan's ability to shake loose the remaining never-Republican counties was compared to Nixon in 1972 (especially because, as few as there were, the majority of those left untouched by the 1984 election--seven of ten--have since ended up voting Republican, some as few as 16 years later). 

There's not really any Democrat since 1964 that one would similarly have expected to turn a large number of the remaining never-Democratic counties. One might have expected Obama, as an Illinoisian, to be able to carry Ogle, IL, but that's just one county anyway. Prima facie, one might have expected Bill Clinton (or perhaps even Jimmy Carter), as Southern Democrats, to have flipped more of the remaining never-Democratic strongholds in the South. (Despite the narrowness of his election, Carter did carry some unionist counties in the South that had last voted Democratic some time ago.) But again, much of what we've seen bears out the partisan hardiness of 'Jacksonians', whether they are loyally Democratic or loyally Republican (to the extent that it is somewhat surprising that Clinton did even carry Union County, Tennessee, an outlier in its state--and region--in this respect; Clinton didn't even carry Searcy County, in his own home state, in either of his elections).

In looking at the never-Democratic counties after the 1972 election, Kentucky stands out: there were six in Kentucky, as compared to one each in Missouri and Tennessee (and none elsewhere in the South apart from the Rio Grande Valley in Texas). After the 1968 election, in contrast, there were 17 never-Republican counties in Arkansas, 20 in Kentucky, and 18 in Tennessee (but only two in Missouri).

Disregarding La Paz, AZ in 1992, Broomfield, CO in 2008, and Manassas City in 2008 as trivial, only George W. Bush in 2000 and John McCain in 2008 have flipped 3 (or more) counties that had never voted for their party before since 1972. (Manassas City first voted in 1976, so it had voted for Bush Sr in 1992 and Dole in 1996.) In both cases, two of the three counties were in Kentucky. 

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As a bonus, what was the election up to which every state still had at least one never-Democratic and one never-Republican county?

(For these purposes I am excluding Hawaii, La Paz County, Arizona, Broomfield County, Colorado, and the independent cities in Virginia whose never-Republicanness briefly overlapped with Colonial Heights' never-Democraticness [nor Colonial Heights' or South Boston's (first voted in 1960) own brief overlaps with the never-Democraticness of Virginia's last never-Democratic counties. I'm not really setting an explicit time limit, but just trying to use some common sense.)

Kentucky: 2016 (Elliott County voted Republican)
Tennessee: 2008 (Stewart County voted Republican)
North Carolina: 1972 (Currituck, Duplin, Gates, Hoke, Lee, and Scotland Counties voted Republican)
West Virginia: 1972 (Webster County voted Republican)
Indiana: 1952 (Brown and Dubois Counties voted Republican)
Maryland: 1952 (Queen Anne's County voted Republican)
New Mexico: 1936 (San Miguel and Valencia Counties voted Democratic)
Missouri: 1932 (Christian County voted Democratic)
Oklahoma: 1932 (Blaine, Garfield, Kay, Kingfisher, Lincoln, Logan, and Major Counties voted Democratic)
Illinois: 1928 (Brown and Greene Counties voted Republican)
Ohio: 1928 (Brown, Holmes, Monroe, Pickaway, and Shelby Counties voted Republican)
Pennsylvania: 1928 (Columbia, Greene, and Monroe Counties voted Republican)
California: 1920 (Colusa and Mariposa Counties voted Republican)
New Jersey: 1920 (Warren County voted Republican)
New York: 1920 (Schoharie County voted Republican)

The two neighbouring states of Kentucky and Tennessee are profoundly deep outliers. Again, for whatever reason, even very staunch unionist strongholds in the cotton states (such as Winston County, Alabama) tended to vote Democratic at least once or twice in the Gilded Age. In time terms, North Carolina and West Virginia fell well short of Tennessee and Kentucky, but all things considered, they, too, are fair outliers. These are those four states.

If we go back to 1952, we still get only six states, out of 48. We also get our first non-Southern state, Indiana. 

By and large, these are Upper Southern states. (And this largely demonstrates that Indiana behaved like an Upper Southern state.) If we keep in mind what Robert David Sullivan said regarding Elliott County, Kentucky:

For more than a century after the Civil War, Kentucky was characterized by deeply Democratic and deeply Republican counties just a few miles apart, representing the split over whether to secede from the Union.

It makes sense the Upper South would retain a juxtaposition of never-Democratic and never-Republican counties for longer than other states. (What is a bit more unclear is why unionist strongholds in the cotton states voted Democratic in the Gilded Age a couple or few times. Perhaps it was something about the state's overall political culture affecting the counties, especially when the War of Sections was still in living memory. In 1904, Theodore Roosevelt carried Winston County, but he did worse in it than he did nationally, getting only 55.2% of its vote. In the same election, he got over 90% of the vote in Sevier County, Tennessee.)

There are a couple other states that seem to be 'missing': Missouri, Arkansas, and Virginia, in particular, all of which either seceded after Fort Sumter or didn't secede at all. Again, for some reason, it seems that unionist enclaves in Ozarkia were less staunchly Republican than their co-unionists in Southern Appalachia. (They were also simply less numerous, it seems. There were a number of unionist enclaves in the Appalachian states that did vote for FDR one or more times.)

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It is worth noting that the county with the longest streak of not voting Republican is not actually a never-Republican county. The oldest never-Republican county is now Brooks County, Texas, which first voted in 1912. There are three counties with longer streaks of not voting Republican, but they have voted Republican at one point: Starr County, Texas (with the longest such streak) last voted Republican in 1892; Northampton County, North Carolina last voted Republican in 1896; and Duval County, Texas last voted Republican in 1904.

This wasn't true before 2016, as Elliott County's first vote was in 1872.

This raises the question of whether there is some metaphysical significance to the fact of a county's never having voted for a given party. 

In a May 2013 article on Elliott County, Eliot Nelson highlighted the significance of the county's long Democratic voting streak and of its never having voted Republican, in the same sentence:

The majority of Elliott's 8,000 residents have cast their ballots for the Democratic presidential candidate in every election since the county was incorporated in 1869 -- the longest continuous stretch of any county in the United States.

Although later on he hints at a special significance to the county's impending first Republican vote being, in fact, its first-ever Republican vote:

When the county supports a Republican presidential nominee -- and recent election results suggest that time might be soon -- it will mark the final victory of conservative social values over progressive economic interests in the region, and the end of a once-powerful Democratic voting bloc whose roots can be traced back to the Civil War.

Albert Menendez similarly pointed out the counties Nixon carried in 1960 that had never voted Republican before 1960 separately from counties he was the first Republican in a very long time to carry, even though some of the latter had longer streaks of not voting Republican than some of the former:

Nixon carried 15 counties in 3 states that had never gone Republican for president before 1960. Five were in Arkansas (Clay, Craighead, Fulton, Randolph, Sharp), four in Missouri (Dunklin, Oregon, Reynolds, Shannon), and two in Oklahoma (Atoka, Garvin). Also included were Houston County, Alabama; Caldwell Parish, Louisiana; Dyer County, Tennessee; and Moore County, Texas.

...

Nixon was also the first Republican since 1868 to carry Marion and Scott Counties, Arkansas, and Madison County, Tennessee. He was the first Republican since 1872 to carry Barnwell County, South Carolina, and the first since 1884 to carry Fayette County, Tennessee.

(Self-evidently, Atoka and Garvin had shorter streaks of not voting Republican than any of these latter-mentioned counties, as did Moore County, Texas, whose first vote was in 1892.) 

If that is so, however, is it really correct to dismiss the 1828 and 1832 elections? I did so because the information source I was using did so. Again, I don't know the reason for said source's doing so; perhaps there is a good reason. As noted here, there were a number of strange characteristics of those two elections (that were not even remotely replicated in later elections).

However, we already know that Union County, PA did vote for Jackson in 1828. If there really is a significance to a county's never having voted Democratic, this would seem to disqualify Union County. Graham Ambrose wrote of Trump's win in Elliott County,

Four years ago, the Manhattan real estate mogul did what Ulysses S. Grant, Theodore Roosevelt, Ronald Reagan, and John McCain could not: He won Elliott County.

Any Democrat who wins Union County, PA in the future could be described as doing something that Wilson, FDR, LBJ, Bill Clinton, and Obama could not do, but not something that Jackson could not do. And, whatever his reputation, Jackson must doubtless still be considered one of the most significant figures in the history of the Democracy, particularly in terms of building a durable national majority coalition.

Aside from Union County, PA, Wikipedia also notes that Wilkes County, NC, Grainger County, TN, and Sevier County, TN voted for Jackson in 1832. (Conversely, Wikipedia includes information about how Vermont's counties voted in 1828 and 1832, and confirms that all those that were never-Democratic as of Halloween 1964 actually were never-Democratic: Addison, Caledonia, Orange, Orleans, and Windsor Counties voted for Adams in 1828 and Wirt in 1832, and Bennington, Rutland, and Windham Counties voted for Adams in 1828 and Clay in 1832.)

This is only an issue for never-Democratic counties, of course, as the Crystal Ball database covers every election contested by the Republican Party. However, there are only 14 counties that we (or I) know have never voted Democratic (because they were founded after the 1832 election): 

Ogle, IL [first election: 1840]
Doniphan, KS [first election: 1864]
Jackson, KY [first election: 1860]
Leslie, KY [first election: 1880]
McCreary, KY [first election: 1912]
Garrett, MD [first election: 1876]
Missaukee, MI [first election: 1872]
Avery, NC [first election: 1912]
Yadkin, NC [first election: 1856]
Johnson, TN [first election: 1840]
Unicoi, TN [first election: 1884]
Colonial Heights City, VA [first election: 1952]
Poquoson City, VA [first election: 1976]
Grant, WV [first election: 1868]

I've never actually come across a source that treated 'not voting Democratic from 1836 on' as tantamount to 'never having voted Democratic'. The closest was Robert Wheel's description of Ogle County, Illinois this way: '[hasn't] voted Democratic ever (since 1836)'. (Funnily, since Ogle was actually founded after the 1832 election, he needn't have hedged this way.)

After a quick search, I couldn't find anything about Obama being the first Democrat ever to carry Carroll County, Illinois, but that wouldn't make any difference because Carroll County was founded after the 1832 election (as were Whiteside County, Illinois and Union County, Tennessee, the two never-Democratic counties that Bill Clinton carried in 1992). There was a mention (and a tweet) of Biden being the first Democrat to carry Riley County, Kansas (although this didn't seem to excite anything like the interest that Elliott County did), but that county obviously was founded after the 1832 election. 

Things get more complicated if we consider the (first) Republican Party (anachronistically called the 'Democratic-Republican Party')--the party of Jefferson, Madison, and Monroe--continuous with the Democratic Party. In the past, it often, indeed generally, has been taken as such (nowadays, the Democracy is less interested in claiming any of its figures prior to FDR as particularly important to its history); and some states did have a popular vote before 1828 (not, however, Vermont). (Indeed, the idea that the first Republican Party was continuous with the Democratic Party might have been part of what led to relatively little talk about Missouri having been a state no Democrat had won without until 2008, as Missouri didn't participate in a presidential election until 1820.) 

In any case, it is certainly quite plausible that the county with the longest streak of not voting Democratic is not a never-Democratic county (as Wilkes, Grainger, Sevier, and Union [PA] have longer streaks of not voting Democratic than do any of the never-Democratic counties founded after the 1832 election). There are certainly counties that have much longer streaks of not voting Democratic (but which have voted Democratic) than the never-Democratic county-equivalent that seems most likely to vote Democratic at some point (Colonial Heights City, Virginia).