How Trump's extremism could help downballot Republicans

This means that an extreme candidate on the political landscape can change how voters see the other candidates on the ballot. It might seem that Trump’s presence at the top of the ticket would cause skeptical voters to flee down-ballot Republicans, just by association. But it could also provide such a stark contrast that suddenly, those other down-ballot names seem reasonable.

Which effect prevails with a Trump-like candidate? We ran an experiment to find out, and presented our findings at the American Political Science Association meeting in September. In our study, we divided up a group of test subjects and presented some of them with a fictitious congressional candidate, Mark Stanton, who was randomly selected to be a Republican or a Democrat and held six issue positions that are generally considered extreme. (When Stanton was a Democrat, this included a fully government-run healthcare system, while as a Republican, his positions included advocating a fully privatized healthcare system and opposition to abortion under all circumstances.) Afterwards, we presented subjects with two more fictional candidates: Don Ochs, a relatively moderate candidate of the same party as Stanton, and then Nicholas Randall, a moderate candidate of the other party.

We presented a similar survey to other subjects, except they were never exposed to the extreme Stanton.

After introducing each candidate, we asked our participants to evaluate the candidates’ ideological positions and tell us how they would vote in an election between Ochs and Randall. We found that those who’d seen Stanton, the extreme candidate, rated his co-partisan as significantly more centrist than those who did not. Importantly, they also said they were more likely to vote for his co-partisan than the opposite-party candidate.