When you look at the big picture of presidential elections, and you try to discern the connection between the White House contest and the 34 Senate elections on the same ballot, it becomes obvious there are two types of years.
The first type we might call “disjointed.” Voters seem to be separating their judgments about these very distinct offices in most competitive races. The presidential candidate who wins adds only a handful — or fewer — additional Senate seats to his party’s total. The presidential coattails are short.
The second type could be termed “intertwined.” The candidates for the White House are very polarizing and distinct, and one or both major-party contenders color the voters’ perceptions of all officeholders on the same partisan label. The party whose letter (D or R) becomes toxic loses a substantial number of Senate seats; thus, the presidential coattails are long.
The second type is somewhat rarer, to judge by the elections for president since World War II, as shown in Table 1. However, the six-year cycles of the three different Senate classes and the current party makeup of each class obviously matter. For instance, the Democrats only gained two net Senate seats in 1964, a seemingly small increase considering Lyndon Johnson’s landslide victory. But six years earlier the Democrats netted 15 Senate seats in the 1958 midterm election, meaning they already controlled a large majority of seats in Class 1, the group of states up in 1964. Conversely, the Republicans won 12 net seats in 1980 when the Democrats entered the cycle controlling 24 of the 34 seats up in Class 3 (which is the same class up in 2016).
No one can say for sure to which category 2016 will belong, but our early expectation is “intertwined.” Considering the rise of Donald Trump, the polarization in U.S. politics, and a higher rate of straight-ticket voting, this could be bad news for the GOP. We have already sketched out a “Trumpmare” doomsday presidential scenario for the Republicans, who control the Senate now by a margin of 54 to 46. Assuming the GOP nominee for the White House is either Trump or Ted Cruz, we think the Democrats will fare reasonably well down-ballot (more so with Trump than Cruz, though Cruz will also have a difficult time carrying many swing states). As shown in Chart 1, in recent presidential cycles, about 80% of states with Senate elections have backed the same party for the presidency and the Senate. In light of the fact that Republicans control 24 of the 34 seats up in 2016, including many in states that President Obama won in 2008 and/or 2012, straight-ticket voting could bode poorly for the GOP.
Indeed, the latest map is good news for the Donks.
Giving the Dems a shot at six seats with two pick-ups likely in Wisconsin and Illinois, is definitely an improvement. That means the Dems would have to keep Harry Reid's seat, and get two more (if Clinton/Sanders wins) or three more (if Trump/Cruz wins).
Pennsylvania and Florida are definitely winnable, as are Ohio and New Hampshire. It's even possible that Roy Blount, Richard Burr, and yes, even John McCain's seats are possible pickups for the Democrats if Trump or Cruz wrecks the place as much as I think they will.
But there are a dozen governor's seats up for grabs in November too, and the biggest ones are Mike Pence in Indiana and Pat McCrory in North Carolina. Sabato's call:
Indiana: One of the surprising margins on Election Night 2012 was now-Gov. Mike Pence’s (R) closer-than-expected win over former state House Speaker John Gregg (D). Pence won by just three percentage points and ran about 4.5 points behind Mitt Romney, who easily carried the state in the presidential race after Barack Obama very narrowly won it in 2008. Gregg is running again. Since winning, Pence has had some shaky moments, most notably a controversy over a 2015 bill that some believed would legitimize discrimination against gays and lesbians. More recently, Pence signed a bill that made Indiana just the second state (along with North Dakota) to outlaw abortions that parents seek because the fetus has been diagnosed with a disability. Gregg, who opposes abortion rights, argues that the bill goes too far. While Indiana is the most conservative state in the Midwest, it’s fair to wonder whether social issues could hurt Pence in his reelection bid. But the bigger problem for Pence is one he shares in common with the other incumbents discussed here: The GOP’s problems at the top of the ticket could potentially trim the Republican presidential nominee’s margins in Indiana, or even allow the Democratic nominee to carry the state, as Obama did once. Obama’s 2008 victory didn’t prevent Pence’s predecessor, Mitch Daniels (R), from easily winning reelection with 58% of the vote, but Pence isn’t Daniels, and he has not yet displayed the kind of crossover appeal that his predecessor enjoyed. Pence remains a favorite in his rematch with Gregg, but we’re moving the race from Likely Republican to Leans Republican.
North Carolina: The Tar Heel State’s statehouse race has always been the marquee gubernatorial contest this cycle. Not only is North Carolina the most populous state holding a gubernatorial race this year, but it’s also one of only two gubernatorial states (the much-smaller New Hampshire is the other) that are likely to be presidential swing states in the event of a close national race. Gov. Pat McCrory (R) has generally had fairly weak approval numbers throughout his time in office, and he is now dealing with a challenge similar to the one Pence faced last year: McCrory just signed a bill that bans cities from creating local policies dealing with gender-identity discrimination and forces transgender students in public schools to use the bathroom that corresponds with their birth gender. There’s been a backlash over the law, and it has so far led PayPal to cancel plans to create 400 jobs in the state. Republicans have long recognized the threat that Attorney General Roy Cooper (D) presents to McCrory, and both sides are gearing up for an expensive, nasty race. Because of incumbency, we were giving McCrory the benefit of the doubt. But no longer: A Donald Trump or Ted Cruz nomination could very well allow the Democratic nominee to win North Carolina, and even if the GOP nominee does carry North Carolina in the fall there’s no guarantee that McCrory will run ahead of the presidential ticket. McCrory’s reelection bid moves from Leans Republican to Toss-up.
I'd love to see Pence and McCrory gone in a Trump/Cruz meltdown that wipes the GOP out in this election cycle, and I'm sure most of you would love it too. Equality issues doing both of them in? Sign me up.