Arizona senator Jeff Flake announced Tuesday that he would not seek re-election to the Senate in 2018. When an incumbent senator decides not to run again, it’s usually easy to gauge the electoral consequences—sitting senators usually perform better than non-incumbents, so if a senator retires in a toss-up state, his or her party becomes less likely to hold the seat and thus less likely to hold the upper chamber.
But the calculus isn’t so simple with Flake. Specifically, Flake wasn’t a standard Republican incumbent, and it’s unclear who is going to come out of the state’s Republican primary, which makes it tougher to gauge how much Democrats benefit from Flake’s departure.
If Flake had run in 2018, it’s not clear that incumbency would have completely outweighed some of his other weaknesses.
According to a model I worked on with Sean Trende at RealClearPolitics, incumbent senators typically perform about three points better than non-incumbents when other factors (e.g. presidential approval in the state, if one of the candidates is especially controversial) are held equal. Three points might not sound like a lot, but in a tightly contested race (and many expected Flake’s 2018 race to be close), incumbency can push a senator across the finish line.
But Flake had some political weaknesses that might have blunted this incumbency advantage. Specifically, he employed a strategy that came be known as “reverse triangulation”—that is, he had a very conservative voting record while publicly criticizing President Trump. When Flake fought with the president, he lost some support from the most Trump-friendly parts of the Republican base and ended up drawing primary challengers, most notably Kelli Ward. And when Flake voted conservatively, he repelled some of the crossover voters that might have made up for that deficit. In other words, Flake’s conflicts with Trump caused him to lose some voters on the right, and his voting record made it difficult to compensate by winning voters on the left and center.
None of this is to say that Flake made the right or wrong choice by taking on Trump while voting conservatively. But the effects of his political strategy showed up in the polls—and threatened both his re-election and re-nomination bids.
Flake’s decision also changes the dynamics of the race by adding an open Republican primary. It’s going to be tough to gauge the state of that race until the field solidifies and reliable pollsters start fielding surveys. If Ward, one of Flake’s controversial and more Trump-friendly challengers, wins the primary then Republicans might have a different type of problem. The RCP model shows that controversial candidates sometimes underperform others by a few points.
But there’s no guarantee that Ward will win. And if the GOP manages to nominate a candidate who can build a coalition more effectively than Flake did, then Flake’s retirement might not end up hurting Republicans’ chances to hold the upper chamber.
