While down-ballot ticket races such as Senate and House elections have become increasingly nationalized–closely correlating with state presidential vote–gubernatorial elections have not followed this path as much. As Harry Enten detailed using 2012 presidential vote and 2014 gubernatorial vote totals, several states went for presidential and gubernatorial candidates of different parties. Examples include Florida, Maryland, Massachusetts, and Wisconsin. In some cases, states chose the same party, but diverged significantly in vote share that got them to that point (e.g. Kansas).
A similar thing occurred in 2016. Among the 12 states that held a governor’s race, Democratic vote share in gubernatorial elections could explain just 29 percent of variation in Democratic vote share in the presidential race. The relationship between the two variables can be seen in the below plot. If all states fell on the 45-degree line, then their gubernatorial and presidential votes would match perfectly. Thus, the further each point (state) diverges from the line, the more unrelated these vote shares are.
Five of the 12 states elected governors from the opposite party of the president that won the state: Vermont, New Hampshire, North Carolina, Montana, and West Virginia. The curious split between gubernatorial and presidential voting at the state level therefore appears to have persisted in 2016. That prompts obvious questions about voting at the individual level: to what degree is cross-party voting occurring? Such a question has implications for the broader study of partisanship, as it appears that party affiliation exerts a different force in presidential and gubernatorial ballot decisions. As a result, it might give a clue about the degree to which voters rely on partisanship or other factors–such as those specific to candidate traits or state conditions–in casting their votes.
Using 2016 CCES data, I was interested in seeing the rates of party voting by election type–presidential or gubernatorial–in the 12 states that had both race types in 2016. I calculate “party voting” as the percent of Democrats who vote for a Democratic candidate and the Republicans who vote for a Republican candidate out of all partisans who expressed a vote choice when asked after the election took place. (Note: the results below do not use vote validation out of sample size concerns, but when using only verified voters, the results are very similar.) The darker blue tinted bars correspond to party voting in the presidential race, while the lighter tinted bars represent voting in each of the state’s gubernatorial races. 95 percent confidence intervals are included for each calculation. While non-overlapping bars do not indicate statistically significant differences, these intervals should give a sense of the accuracy of each percentage which is informative for understanding party voting rates.
Few large divergences between presidential and gubernatorial party voting rates appear. Across most of the states here, people vote their party to similar (high) degrees, whether it’s a governor’s or president’s race. However, a few trends are notable. In Montana, one of the states that went to different parties, the party voting rate was 10.5 percentage points higher in the presidential race than in the gubernatorial race. 17 percent of Montanan partisans voted for a candidate outside their own party, suggesting some split-ticketing voting taking place. That should help clarify why the Democratic gubernatorial candidate (Steve Bullock) did 14 percentage points better than the Democratic presidential candidate (Hillary Clinton) did, for example.
Similarly, a statistically significant difference occurs in New Hampshire in the party voting rates by race type. While 94.9 percent of partisans voted for their co-party candidate in the governor’s race, fewer in the presidential race did at 88.5 percent. This split likely made the pairing of a Democratic presidential win and Republican gubernatorial win possible. One other mixed result state sees this type of split–West Virginia, which had a 84.6 party voting rate in its presidential race but only a 70.2 rate in the gubernatorial rate. West Virginians voted their party at a higher rate on the presidential ballot than on the gubernatorial ballot, possibly paving the way for a Democrat wining the governor’s office and a Republican winning the state at the presidential level.
Interestingly, this comparison sheds little light in the case of Vermont, where a Democrat in Clinton won 61.1 percent of the presidential vote but a Republican in Phil Scott won 52.9 percent of the gubernatorial vote. Party voting does not diverge by much by race type. I looked to see whether behavior by non-partisans (pure Independents) could be driving the different results, but little difference by race type appears there as well. Limitations of the survey data used may be at play here, as the sample of Vermonters has more Democratic voters for the governor’s race than it should (a 50-45 Democratic advantage among those surveyed even though it should be closer to 53-44 Republican).
Regardless, differing party voting rates may have played a role in the divergent presidential/gubernatorial race outcomes in West Virginia, Montana, and New Hampshire. Not only does that offer an indication of when partisanship exerts less of a force on vote choice, but it also might bear meaning for when races become nationalized or not. As Dan Hopkins discusses in the description for his forthcoming book, these patterns–especially from the first figure–could indicate the level of nationalization of a race, when a down-ballot candidates become tied to their national party and presidential candidate, and even whether party voting activation corresponds to nationalization of an election.
Agadjanian Politics 