There was a great deal of talk during the 2016 presidential campaign about Democratic nominee Hillary Clinton’s “blue wall” in the Electoral College, with “blue” the color news organizations use to denote states won by Democrats.
The basis of this talk was simple. In general, states tend to vote similarly for president over time; the average correlation between state-level margins (Democratic % – Republican %) in successive elections since 1984 is 0.95. Eighteen states and the District of Columbia (DC), with a total of 242 electoral votes (EV), had voted for the Democratic presidential nominee in six consecutive elections (1992-2012). Three other states—Iowa (6 EV), New Hampshire (4 EV) and New Mexico (5 EV)—had voted for the Democratic nominee in five of these six elections.
Thus, the thinking went, the 2016 Democratic nominee for president would start the general election with an all-but-guaranteed 242-257 EV (of the 270 needed to win the presidency). Add three Democratic-trending states won by Barack Obama twice—Colorado (9 EV), Nevada (6 EV) and Virginia (13 EV)—and there seemed to be at least 270 EV seemingly a lock for any Democratic nominee.
And that was without two “swing” states that had voted for the Democratic presidential nominee in three (Florida; 29 EV) and four (Ohio; 20 EV) of the previous six elections, including for Obama twice.
Hillary Clinton was a shoo-in to beat Republican Donald Trump in 2016, according to this logic.
Despite winning the popular vote by 2.1 percentage points, she lost the Electoral College 306-232, 10 EV less than the bare minimum she supposedly had banked.
There were always flaws in the “blue wall” argument, but two are most relevant here.
One, state voting patterns change over time. From 1968 through 1988 it was the Republicans who had an even-more-impregnable “red wall,” with 22 states voting for the Republican presidential nominee in six consecutive presidential elections and 13 other states doing so in five of them. The Republicans won the White House in five of these six elections, averaging 417 EV.
Ask President George H. W. Bush how that “red wall” helped him in 1992, when he only won 168 EV (and 23 fewer states than in 1988) in losing to Democrat Bill Clinton.
Two, the Democratic nominee won the presidency four times between 1992 and 2012, averaging 327 EV. The Democrats also won the popular vote in 2000, while losing the Electoral College and, thus, the White House. The one time Democrats lost the popular vote AND the Electoral College in these years, in 2004, John Kerry still won 251 EV (and 48.3% of the popular vote).
By definition, if you win at least two thirds of the presidential elections in a 20 year span, you are likely winning a significant number of states regularly. And you are likely winning some states by smaller margins than your national margins.
Consider Obama’s reelection bid in 2012, when he beat Republican Mitt Romney in the popular vote by 3.8 percentage points, capturing 332 EV.
Obama won two states—Ohio (D+3.0%) and Florida (D+0.9%)—by less than his national margin. Remove those two states, and his EV total drops to 283. Remove Virginia, which he won by 3.9%, just barely above his national margin, and his EV total drops to 270—exactly the number needed to win. If Obama had lost these three states plus either Colorado or Pennsylvania (both D+5.4%), Romney would have won.
Simply put, when one political party is generally winning the national popular vote, often by large margins, as the Republicans did from 1968 to 1988 (average R+9.6%), and the Democrats did from 1992 to 2012 (average D+3.9%), that party sweeps more “marginal” states into its column. Electoral college “locks” are illusory at worst, and transient at best.
As a long-time student of American electoral geography, I maintain an Excel workbook containing every state’s Democratic and Republican presidential vote for every election since 1984, using data from Dave Leip’s indispensable Atlas of U.S. Elections. This dataset allows me to calculate every state’s “Relative Democratic Margin” (RDM) since 1984.
RDM = (state D% – state R%) – (national D% – national R%)
Consider North Carolina, which Obama won by 0.3 percentage points in 2008, then lost by 2.0 percentage points in 2012. Obama beat Republican John McCain nationally in 2008 by 7.3 percentage points. Subtracting 7.3 from 0.3 yields -7.0; North Carolina was 7.0 percentage points less Democratic than the nation in 2008. In 2012, RDM was -5.8 percentage points (-2.0 – 3.8). Thus, North Carolina shifted 1.2 percentage points toward the Democrats, relative to the national vote, between 2008 and 2012.
Multi-election average RDM’s can also be calculated for each state: averages smooth out idiosyncratic voting behavior from a specific election. For example, presidential and vice presidential nominees tend to do slightly better in their home state than its partisan voting history would predict. Consider also Michigan. Democrats won the state in each presidential election from 1992 to 2004 by an average of 7.3 percentage points. Obama won Michigan by 16.4 percentage points in 2008 and 9.5 percentage points in 2012, margins that were likely inflated by strong approval of the auto industry bailout spearheaded by the Obama Administration.
We now know that this history was not especially predictive of 2016, when Trump won Michigan by 0.2 percentage points, dropping its RDM to D-2.3 from D+5.6 (2012) and D+9.2 (2012).
Like I said, oops.
I elected to “weight” average RDM by election recency. The formula I use to calculate a three-election weighted RDM (3W-RDM) is:
(Election 1 RDM + 2*Election 2 RDM + 3*Election 3 RDM)/6
The most recent election thus contributes 50% of the value of the 3W-RDM. Weights and time-frame are admittedly arbitrary. However, there is no discernible difference in the relative ordering of states using alternate weights and time-frames.
For example, the 3W-RDM for Pennsylvania, 2004-2012 is thus:
(5.1 + 2*3.1 +3*1.5)/6 = (5.1+6.2+4.5)/6 = 15.8/6 = 2.6
Using this method, Hillary Clinton’s projected 2016 margin in the Keystone state would have been 2.6 + 2.1 = 4.7 percentage points.
Instead, Ms. Clinton lost Pennsylvania by 0.7 percentage points, 5.4 percentage points lower than expected.
The “projected” 2016 margin for each state can be compared to its actual 2016 margin to see how well the “blue wall” thesis actually held up. Table 1 presents theses values.
Table 1: Projected and Actual 2016 State-level Margins (Democratic % – Republican %)
|State||EV||Projected 2016 Margin (D% – R%)||Actual 2016 Margin (D% – R%)||Actual Margin – Projected Margin|
On average, Hillary Clinton’s state-level margin was 2.3 percentage points lower than projected; she underperformed in 31 states (average=-6.7 percentage points), while over performing in 19 states plus DC (+4.5 percentage points). While 2.3 is not an especially large deviation given that each projection is based on only three data points, she still underperformed 61% of the time.
In fact, she lost five states (70 EV) she was projected to win by an average of 5.0 percentage points: Michigan, Wisconsin, Pennsylvania, Iowa and Ohio, although the latter was projected to be very close. Hillary Clinton lost these contiguous Rust Belt/Midwestern states by an average of 3.8 percentage points; Obama had won them by an average of 6.1 percentage points four years earlier. Overall, these five states shifted 8.2 percentage points more Republican relative to the nation from 2012 to 2016.
By contrast, Trump did not lose a single state he was projected to win.
There were 19 states in which Hillary Clinton underperformed her projected margin by five or more percentage points, six of which she underperformed by 10 or more percentage points: Maine (where she lost 1 EV), West Virginia and four contiguous Midwestern states (Missouri, Iowa, South Dakota, North Dakota). In fact, she underperformed in the 12 Midwestern states by 7.7 percentage points, by far the worst of any region.
Hillary Clinton over performed her projected margin by five or more percentage points in only six states: Georgia, Alaska, Arizona, Texas, California and Utah. Third-party candidates, including Utah native Evan McMullin and Libertarian Gary Johnson, did better than expected in Utah (27.8% combined) and Alaska (12.2%), holding down Trump’s percentage in those states. After DC (D+86.8%) and Hawaii (D+32.2%), California was Hillary Clinton’s best state: she won the state by 30.0 percentage points.
Georgia, Arizona and Texas are intriguing future targets for the Democrats, however. Hillary Clinton lost their combined 65 EV by an average 5.9 percentage points, a five percentage point improvement from 2012. They also shifted an average 7.6 percentage points more Democratic relative to the nation from 2012 to 2016.
The final question, then, is what other state- and regional-level shifts can be discerned from these data. One way to assess this is to examine changes in consecutive 3W-RDM. For example, following the 1992 presidential election, Nevada had a 3W-RDM of -8.5%. Over the next six elections, Nevada’s had 3W-RDM scores of -6.9, -5.0, -2.5, 2.0, 3.2 and 2.0, a weighted-average shift of 1.4 percentage points more Democratic every election.
Table 2: Average Weighted Trends in State-Level 3W-RDM, 1984-1992 to 2004-2012 and to 2008-2016, and Projected Democratic Margins in 2020
|State||EV||Weighted Average Election Year Change in 3W-RDM,
|Weighted Average Election Year Change in 3W-RDM,
|Projected 2020 Margin (D% – R%) Adjusted for Trend|
What jumps out first from Table 2 is that there was no clear a priori evidence that Hillary Clinton was in a precarious position in the five key states she lost (adding some support to the “blue wall” thesis). In fact, there was evidence that Democrats’ relative position Michigan, Ohio and Wisconsin was IMPROVING by a weighted-average 0.6 percentage points each election cycle. There was slight evidence of movement away from the Democrats (-0.3%) in Iowa and Pennsylvania, but even then Democrats were still projected to win those states by about four percentage points in 2016.
“Trends” often become apparent only after the fact, unfortunately. Once the 2016 election results are added, the weighted-average trend shifted an average of 1.3 percentage points more Republican in these five states.
In other states, however, 2016 continued a clear strong pro-Republican trend. Nine states had a weighted average trend of at least -2.8 percentage points after both the 2012 and 2016 presidential elections; excepting Wyoming, these states form a contiguous band running from West Virginia (shifting away from the Democrats’ national margins at a rate of 8.8 percentage points per election!) south and west through Kentucky, Tennessee and Alabama, through Missouri, Arkansas and Louisiana into Oklahoma. Add in the Dakotas (and the five Rust Belt/Midwestern states discussed above), and there is clear evidence that a large swath of “flyover” states are trending strongly and steadily away from the Democrats.
At the same time, in 2016, Democrats halted trends away from them in four states: Utah, Georgia, Texas and Arizona. The reversal in Utah likely results from McMullin’s strong 2016 performance there; the Democratic presidential nominee is still projected to do 32.5 percentage points WORSE there than nationally in 2020. And while there are hopeful signs for the Democrats in Arizona, Georgia and Texas, these projections suggest they would still need to win the 2020 presidential by 10-15 percentage points to have a chance to WIN any of those states. Still, as 2016 showed, election-to-election shifts of eight or more percentage points can occur.
Five states continued to trend strongly pro-Democratic (minimum +2.4 percentage points after both 2012 and 2016): Virginia, Maryland, Vermont, California and Hawaii. The latter four, however, were already firmly in the Democratic column (Hillary Clinton won them by an average 28.8 percentage points).
Three other states with at least 1.0 percentage point pro-Democratic shifts in 2012 and 2016 are worth noting: Colorado, Nevada and North Carolina. Along with California, New Mexico and Arizona, Democrats are steadily improving their relative position in the southwestern United States. And Virginia, North Carolina and Georgia are all southeastern states bordering the Atlantic with large urban centers.
It is, of course, possible that the narrow (but Electoral-College-decisive) Trump victories in Michigan, Wisconsin and Pennsylvania that delivered him the White House were idiosyncratic results of the unusual 2016 elections. This would mean that projected presidential vote margins, such as those presented here, still have broad predictive value.
It is perhaps more likely, however, that the broad geographic center of the country is moving steadily away from the Democrats, while a U-shaped swath of states—New England and the Mid-Atlantic south along the Atlantic seaboard to Georgia (minus South Carolina), jumping west to Texas and the southwest, moving up the Pacific Coast to Washington, plus Hawaii—is moving steadily toward the Democrats. Add in the Democratic strongholds of Illinois and Minnesota (maybe), and this latter group of states (and DC) contains 304 EV, although that includes the combined 65 EV in Arizona, Georgia and Texas (and 25 less-certain EV in Minnesota and North Carolina).
I conclude, then, with this geography question for Democrats:
Does your future lie with the disaffected white rural blue collar voters of the Rust Belt (whose dramatic shift toward Trump in 2016 proved decisive), or does it lie with the African-American, Hispanic and college-educated white voters of the southeast and southwest?
Until next time.
 California, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Washington, Wisconsin
 Literally, as a political science major at Yale, and later as an ABD doctoral student at Harvard.
 I have calculated five-election weighted averages [weights=1,2,3,4,5], used a three-election weight scheme of 1,3,5) and used no weights at all.
 Weight scheme=1,2,3,4,5,6