The Not-So-Changing Geography of U.S. Elections

On November 3, 2020, Democrats Joe Biden and Kamala Harris were elected president and vice president, respectively, of the United States. According to data from Dave Leip’s essential Atlas of U.S. Presidential Elections, the Biden-Harris ticket won 51.3% of the nearly 158.6 million votes cast. Turnout shattered the previous record of 137.1 million votes cast in 2016: 15.6% more votes were cast for president in 2020 than in 2016. The incumbent Republican president and vice president, Donald Trump and Mike Pence, won 46.8% of the vote, with the remaining 2.0% going mostly to the Libertarian and Green tickets

While the 4.5 percentage point (“point”) margin for Biden-Harris over Trump-Pence—7.1 million votes—was solid, it is the Electoral College which determines the winner of presidential elections. Despite objections to the counting of the votes from individual states and an armed insurrection aimed to stop the Congressional certification of Electoral Votes (“EV”), the Biden-Harris ticket was awarded 306 EV—36 more than necessary—to 232 for Trump-Pence.

In many ways, the 2020 presidential election was a near-perfect encapsulation of recent presidential elections. Between 1992, when Democrats Bill Clinton and Al Gore were elected president and vice president, ending 40 years of Republican White House dominance, and 2016, the Democratic presidential ticket averaged a 3.6-point winning margin and 313.7 EV, very close to 4.5 points and 306 EV.

Biden-Harris improved on the 2016 Democratic margin in the national popular vote by 2.4 points, winning 16.4 million more votes than the ticket of Hillary Clinton and Tim Kaine; Trump-Pence won 11.3 million more votes, while third party candidates won 5.2 million fewer votes. Moreover, across the 50 states and the District of Columbia (“DC”), the Democratic ticket improved by an average of 3.1 points! In the EC, as Table 1 shows, Biden-Harris carried five states Clinton-Kaine lost in 2016: Arizona, Georgia, Michigan, Pennsylvania and Wisconsin; no states flipped the other direction.

Table 1: States with Presidential Election Margins <5.0 Points in 2016 and/or 2020

StateEV2016 Margin (Dem-Rep)2020 Margin (Dem-Rep)2020-2016
  %#%#%#
Florida29-1.2-112,911-3.4-371,686-2.2-258,775
North Carolina15-3.7-173,315-1.3-74,483+2.4+98,832
Arizona11-3.5-91,2340.3+10,457+3.8+101,691
Georgia16-5.1-211,1410.2+11,779+5.3+222,920
Wisconsin10-0.8-22,7480.6+20,682+1.4+43,430
Pennsylvania20-0.7-44,2841.2+82,166+1.9+127,450
Nevada62.4+27,2022.4+33,596-0.03+6,394
Michigan16-0.2-10,7042.8+154,181+3.0+164,885
Minnesota101.5+44,5937.1+233,012+5.6+188,419
New Hampshire40.4+2,7367.4+59,277+7.0+56,541
Maine43.0+22,1429.1+74,335+6.1+52,193
Colorado94.9+136,38613.5+439,745+8.6+303,359

Clinton-Kaine won Virginia by 5.3 points in 2016; four years later Biden-Harris won the state by 10.1 points, a 4.8-point jump. The shift in Texas was similar, from a 9.0-point loss to “only” a 5.6-point loss, a 3.4-point improvement. In fact, Biden-Harris did better than Clinton-Kaine in every close state except Florida, losing by 258,775 votes more than in 2016. Overall, the only other states where the Democratic margin was at least 0.1 points worse in 2020 were Arkansas (-0.7), California (-0.8), Utah (-2.4) and Hawaii (-2.7). By contrast, Biden-Harris improved by at least 6.0 points (roughly double the state average) in the close states of Maine (6.1), New Hampshire (7.0) and Colorado (8.6), as well as Massachusetts (6.3), Connecticut (6.4), Maryland (6.8), Biden’s home state of Delaware (7.7) and Vermont (9.0).

Had Clinton-Kaine flipped just 77,736 votes in Michigan, Pennsylvania and Wisconsin in 2016, Democrats would have retained the White House, 278-260. By the same token, had Trump-Pence flipped just 65,009 votes in Arizona, Georgia, Wisconsin, and the 2nd Congressional District of Nebraska (“NE-2”), they would have been reelected, 270-268—while still losing the national popular vote by 4.5 points. Wisconsin, which shifted only 1.4 points—43,430 votes—toward the Democrats, was a key pivot state in both elections, with Pennsylvania right behind.

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To better understand the relative partisan leans of each state, I developed 3W-RDM, a weighted average of how much more or less Democratic than the nation as a whole a state voted in the three most recent presidential elections. Basically, it is what I estimate the state-level margin between the Democratic and Republican nominees would be if they tied in the national popular vote. Note, however, that 3W-RDM (plus national popular vote) has missed the actual state-level result by an average of 5.3 points in recent elections. Figure 1 and Table 2 show current 3W-RDM for every state, based upon data from the 2012, 2016 and 2020 elections. Table 2 also lists 3W-RDM based upon data from 1984-92 and 2008-16.

Figure 1: Current State Partisan Lean, Based Upon 2012-20 Presidential Voting

Table 2: Current and Historic State Partisan Lean (3W-RDM), Sorted Most- to Least-Democratic

State2020 EV1984-922008-162012-20Ave. Change 1992-2020
DC375.382.082.71.0
Hawaii49.834.329.02.7
Vermont36.627.728.93.2
Maryland108.022.626.22.6
Massachusetts1114.222.126.11.7
California555.623.224.92.7
New York2910.821.620.21.3
Rhode Island415.118.016.60.2
Connecticut70.712.813.91.9
Washington126.912.113.71.0
Illinois207.114.713.30.9
Delaware3-0.512.512.81.9
New Jersey14-4.012.012.02.3
Oregon77.38.710.10.4
New Mexico52.06.56.30.6
Colorado9-2.42.25.71.2
Maine4-0.55.94.50.7
Virginia13-10.41.53.92.0
Minnesota1011.01.51.8-1.3
New Hampshire4-11.60.11.21.8
Nevada6-8.52.0-0.51.1
Michigan160.72.2-0.7-0.2
Pennsylvania205.3-0.4-2.3-1.1
Wisconsin104.70.7-2.4-1.0
Florida29-10.7-3.4-5.50.7
North Carolina15-7.0-6.0-5.80.2
Arizona11-10.9-9.7-6.10.7
Georgia16-7.0-9.6-6.50.1
Iowa68.0-4.7-9.8-2.6
Ohio18-3.0-5.8-9.8-1.0
Texas38-7.7-15.3-12.0-0.6
Alaska3-15.7-19.2-15.80.0
South Carolina9-13.9-15.7-15.9-0.3
Missouri103.2-15.9-19.0-3.2
Indiana11-10.9-16.3-19.6-1.2
Mississippi6-12.6-18.5-19.7-1.0
Montana3-1.6-18.6-20.8-2.7
Kansas6-9.8-23.4-21.3-1.6
Louisiana8-2.0-22.2-22.3-2.9
Nebraska5-19.7-25.8-25.1-0.8
Tennessee11-3.0-25.8-27.2-3.5
Utah6-26.2-33.1-27.6-0.2
Alabama9-10.7-28.4-29.2-2.6
South Dakota3-5.5-25.8-29.6-3.4
Arkansas63.3-28.2-30.3-4.8
Kentucky8-2.9-28.7-30.3-3.9
Idaho4-20.3-34.2-34.8-2.1
North Dakota3-12.7-29.4-35.4-3.2
Oklahoma7-13.4-38.1-37.8-3.5
West Virginia59.2-35.5-41.4-7.2
Wyoming3-14.5-45.7-47.5-4.7
AVERAGE -1.3-4.6-5.1-0.5

The core Democratic areas are primarily where they have been for 30 years: New England (average 3W-RDM: D+15.2), the Pacific Coast minus Alaska (D+12.4), the mid-Atlantic minus Pennsylvania (D+22). These 15 states and DC contain a total of 183 EV. Add the Midwestern states of Illinois (20 EV) and Minnesota (10), and the southwestern states of New Mexico (5) and Colorado (9), and the total rises to 226 or 227, depending upon Maine’s 2nd Congressional District (“ME-2”). This is the current Democratic presidential baseline, 44 EV from 270.

The core Republican areas are also primarily where they have been for 30 years: Mountain West plus Alaska minus Colorado (R+29.2); the six states running south from North Dakota to Texas (R+26.9); the five states in the western half of the Deep South (R+25.8); the border states of Missouri, Kentucky and West Virginia (R+30.3); and the Midwestern states of Iowa, Indiana and Ohio (R+13.1). Add the southern Atlantic states of North Carolina, South Carolina, Georgia and Florida, plus Arizona, and the total is 258 or 259 EV, depending upon NE-2. Each of these 27 states is at least 5.5 points more Republican than the nation, making it the current GOP presidential baseline, just 12 EV from 270.

Two states totaling 22 EV would be balanced on a knife’s edge: Michigan and Nevada. In 2016, they split, with Republicans winning the former and Democrats winning the latter. Biden-Harris won both in 2020.

That leaves two states totaling 30 EV—Pennsylvania (R+2.3) and Wisconsin (R+2.4); they lean more Republican than the “core” Democratic states of Minnesota and New Hampshire. Add them to the “core” Republican 258 EV, and Republicans enter a presidential race tied in the national vote—or even a point behind—with a minimum of 288 EV, 18 more than necessary. Michigan, Nevada, NE-2 and ME-2 would get them to 312.

I made this same point here, when I used a simple ordinary least squares (“OLS”) regression model of EV and national popular vote margin to show that in a dead-even national election, Republicans would—on average—be favored to win the EC 283-251, with four EV going to third-party tickets. Adding data from 2020 does not materially alter this estimate, which is essentially Republicans winning their 258 EV plus Pennsylvania and Wisconsin: 288 EV. Democrats then win their core states plus Michigan, Nevada, ME-2 and NE-2: 250 EV.

Here are the updated OLS regressions:

Democrats:               Electoral Votes = 1232.9*Popular Vote Margin + 250.98

Republicans:            Electoral Votes = 1229.2*Popular Vote Margin + 283.04

Simple algebra shows Democrats need to win nationally by 1.5 points to be on track to win 270 EV, while Republicans could lose nationally by 1.1 points and be on track to win. Put another way, Republicans could theoretically lose the national popular vote by 2.3 points and still win 288 EV, given the imbalance in the Electoral College.

Paradoxically, however, Democrats have won the EC in five of the last eight presidential elections, because they win the national popular vote by large enough margins. The 3.5-point average margin in those eight elections translates to an estimated 294 EV, on average: winning their core 226, plus Michigan, Nevada, ME-2, NE-2, Wisconsin, Pennsylvania (280 EV total) plus one of North Carolina, Arizona or Georgia. As we saw, the Biden-Harris ticket won all but ME-2 while adding Arizona and Georgia, losing North Carolina by just 1.3 points.

This imbalance has been getting worse over time. In the mid-1990s, after the Republican ticket won by landslides in 1984 and 1988 and Clinton-Gore won by a slightly smaller landslide in 1992, the average state was only 1.3 points more Republican than the nation, far lower than the roughly 5.0 points of recent elections. In a dead-even national election—essentially what happened in 2000—Democrats would have had a slightly higher base, ~230 EV from 18 states plus DC at least D+2.0, with the ~30 EV of Michigan, Connecticut, Maine and Delaware within 1.0 points either way. Democrats would start closer to 250 than 230 votes in this scenario, though there would still be ~275 EV from 27 states at least R+2.0; throw in Montana (R+1.6) and the total increases to 278. Still, Democrats were far closer to parity in the EC in the mid-1990s than they are now.

What changed?

Figure 2: Average Change in State Lean Since 1984-92

As Figure 2 clearly shows, the strength of state-level partisanship sharply increased over time: Democratic states become somewhat more Democratic, while Republican states became dramatically more Republican. Not only did the average state shift 3-4 points more Republican, relative to the nation, but the variance widened. After the 1984-92, the standard deviation—a measure of how narrowly or widely values are spread around the mean—increased from 14.4 to 23.4 after the 2012-20 elections. Moreover, consider states at least 3.5 points more partisan than the nation. In the mid-1990s, those states averaged D+12.8 and R+12.0; today, those values are D+19.5 (213 EV) and R+22.4 (259 EV).

The biggest pro-Democratic shifts, based upon the average three-election-cycle change in 3W-RDM since 1984-92, occurred in Vermont (average: D+3.2), the Pacific states of California and Hawaii (each D+2.7), and the mid-Atlantic states of Maryland, New Jersey, Virginia and Delaware and New York (mean: D+2.0). Colorado, Nevada, and the remaining New England states except Maine also shifted noticeably more Democratic. At Colorado, Nevada and Virginia even switched from core Republican states to core Democratic/swing.

But these shifts are miniscule compared to two blocks of Republican states. The first block I call the “upper interior Northwest”: Idaho, Montana, Wyoming and the Dakotas. These five states became an average 3.2 points more Republican every cycle since the mid-1990s. The second block I loosely call “Border,” though I could also call them “White, Culturally Conservative”: Oklahoma, Missouri, Arkansas, Tennessee, Kentucky and, most extremely, West Virginia. These six states became an average 5.3 points more Republican every cycle since the mid-1990s. West Virginia, in fact, is almost in a category by itself. Following the 1992 presidential election, when Clinton-Gore won it by 13.0 points, it has become an astonishing 7.2 points more Republican each cycle since then; Trump-Pence won it in 2020 by 38.9 points, a 51.9-point pro-Republican shift!

In fact, seven states—Arkansas, Kentucky, Oklahoma, South Dakota, Tennessee, West Virginia and Wyoming—shifted further Republican over 28 years than any state shifted Democratic over those years. West Virginia is also joined by Arkansas, Iowa, Missouri, Pennsylvania and Wisconsin as states that shifted from core Democratic to core Republican/pivot states.

As for why states shifted strongly Democratic or Republican, I wrote here about the growing partisan divide between white voters with (Democratic) or without (Republican) a college degree. Other explanations include self-sorting by geography (Democrats to the coasts, Republicans to “flyover” country) and information (Democrats from traditional media, CNN and MSNBC; Republicans from right-wing media and Fox News).

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Thus far, I have only looked at presidential elections. Table 3 lists the percentages of United States Senators (“Senators”), Governors and Members of the United States House of Representatives (“House Members”) who are Democrats in the core Democratic, swing/pivot (Michigan, Nevada, Pennsylvania, Wisconsin) and core Republican states. Data on the partisan split of each House delegation, based upon the results of the 2020 elections, may be found here.

Table 3: Democratic Percentage of Senators, Governors and House Members in Three Groups of States

GroupSenatorsGovernorsHouse Members
Core Democratic (n=19)97.4%*78.9%76.9%
Swing/Pivot (n=4)75.0%100.0%50.0%
Core Republican (n=27)13.0%14.8%27.8%
* Includes two Independents, Angus King of Maine and Bernie Sanders of Vermont, who caucus with Democrats.

While not a perfect overlay, these percentages tell a simple story: states that lean Democratic at the presidential level strongly tend to elect Democrats to statewide office, while states that lean Republican at the presidential level strongly tend to elect Republicans to statewide office. Thus, only five of 57 (8.8%) Democratic-state Senators and Governors are Republicans: the indomitable Senator Susan Collins of Maine, and the governors of Maryland, Massachusetts, New Hampshire and Vermont. By the same token, only 11 of 81 (13.6%) Republican-state Senators and Governors are Democrats: all four Senators from Arizona and Georgia; one Senator each from Montana, Ohio and West Virginia (political-gravity-defying Joe Manchin); and the governors of Kansas, Kentucky, Louisiana and North Carolina. In other words, only 16 of 138 (11.6%) Senators and Governors from these 46 states are from the “opposition” party. Curiously, in the four swing/pivot states, every governor and Senator except Senators Pat Toomey of Pennsylvania and Ron Johnson of Wisconsin—the pivot states—are Democrats. The House percentages are a bit murkier, reflecting Republican pockets in “Democratic” states and Democratic pockets in “Republican” states, but it is still the case that roughly ¾ of the House delegations from these 46 states “match” their state’s partisan lean; swing/pivot states are split literally down the middle: 22 Democrats and 22 Republicans.

Pick your cliché. “All politics is local.” Clearly, not any more, as elections become increasingly nationalized. “I vote the person, not the party.” Apparently no longer true, given how closely voting for president/vice president, Senate, governor and House track. “Vote the bums out.” Well, voters seem to prefer bums from their party to anyone from the other party. As I noted with gerrymandering, these trends, if they continue, may be far more damaging for our two-party democracy than for either political party.

Until next time…please stay safe and healthy…

Published by Matt Berger

I am a data geek, writer, investigator and film noir devotee with academic training in political science (Yale BA, Harvard MA), biostatistics (Boston University SPH MA) and epidemiology (Boston University SPH PhD). In January 2021, I finished writing Interrogating Memory: Film Noir Spurs a Deep Dive Into My Family History...and My Own for which I seek a publisher. In Chapter 6: So...What Is Film Noir, Again?, I analyze my film noir database, which contains 4,825 titles. My musical holy trinity is Genesis, Miles Davis and Stan Ridgway. I am a liberal Democrat who understands a thriving democracy requires at least two mature political parties. I grew up just outside Philadelphia, and I live just outside Boston, where my wife and daughters keep me happy, sane and grounded. Please ask me anything else you want to know.

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