Winning the election would turbocharge Trump’s worst impulses. He would have new grounds to ignore GOP leaders and indulge his every whim. If that approach gets him elected, why would he behave any differently as president?

Maybe Trump would drag the country through four years of chaos and stagnation, trailing broken promises and aborted schemes. Or maybe he would handle the job so irresponsibly that he would provoke his impeachment and removal—an eminently plausible scenario.

The latter outcome would have some special downsides for Republicans. One is that it would saddle them with the herculean chore of defending him at his worst. Another is that it would derail any policy ideas they hope to advance. Then there’s the political cost in the next election.

Compared with these nightmares, a Hillary Clinton presidency would have all sorts of advantages. It would give Republicans a unifying focus, mobilize them to block liberal policies, open the way for new conservative leaders to emerge and offer the party a chance to rebound at the polls in 2018. If she were to be embroiled in a White House scandal brought on by her own disregard for the rules, even better for the GOP.