But, in his day job, Wilentz is Professor of American History at Princeton University, where has taught since 1979, and written books on everything from The Rise of American Democracy: Jefferson to Lincoln, to The Age of Reagan: A History, 1974–2008. More than most, he's well positioned to talk about what, in the bigger scheme of things, a Trump presidency could mean for the American political system. Above, Wilentz contends that we'd have a "crisis presidency," hopefully constrained by the checks and balances built into our constitution. And he suggests that, if history offers any guide, the nativism fueling the Trump campaign could spell doom for the GOP. Whenever a party runs on "Making America Great Again," says Wilentz, it "usually means that the party is going to fall under great pressure--it's going to, if not collapse entirely, disintegrate or get pushed to the margins." Few GOP leaders, Lindsey Graham excepted, seem to really get that. But can we really expect political nonentities to see that you're actually losing when you think you're winning?