Everyone is underestimating Trump. It could hurt Democrats and Republicans alike.

Republicans probably can’t plan too much for what would happen if Trump loses. Whether Trump exits in 2025, 2021 or sooner, the party seems destined for a post-Trump identity crisis. Instead, Republicans should make sure they have a plan for what to do if Trump wins.

Trump seemed to come into office with clear policy instincts but with a less clear ideology. He was an immigration hard-liner who wanted to undo President Barack Obama’s legacy and avoid committing himself to a Paul Ryan style of fiscal conservatism. But when he took office, he basically spent his political capital on less-than-popular parts of the Ryan agenda (i.e., traditional GOP tax cuts and attempting to repeal and replace the Affordable Care Act). If Trump gets a second term, he might, depending on the results in the House and Senate, have the chance to try to create a more coherent policy vision. A competent president would try for that.

Maybe more importantly, a second Trump term would shape the long-term trajectory of the GOP. No matter what happens in 2020, the GOP will have to figure out which elements of Trump-ism they should keep (maybe an openness to violating orthodox libertarian economics) and which parts need to be memory-holed fast (a “both sides” approach to events such as the white nationalist rally in Charlottesville). But if Trump wins twice, it will be harder for the rest of the GOP to argue with the Trumpists. In that case, the GOP will have a serious planning challenge — trying to create a coherent policy platform that works for an increasingly diverse country while Trump’s face is stamped on your party. The GOP should take this possibility just as seriously as the chance that he loses in a landslide and start planning for it. An unexpected victory can turn contain the seeds of future defeats.