In 2015, Trump was promising to deport what he called “rapists and criminals.” People like me, Democrats, sat horrified. We’d never heard anyone talk that way because in our world, you didn’t. As mostly white, mostly educated, mostly upper-middle-class people, we would never dare speak of non-white people that way, much less think of them that way. Trump, we concluded, had to be a racist. That wasn’t the only proof we had. But it became one of the biggest fights for the Democrats.