Trump isn’t Hitler; he isn’t Father Coughlin; he isn’t even Henry Ford (whose racism was theoretical rather than opportunistic like Trump’s). History can’t shed much light on Trump, because it’s written by winners. We read it as a parable of progress, in which, thanks to the checks and balances that the Federalists carefully wrote into the Constitution and our own better nature, the worst impulses of the democratic mob have consistently been foiled. Slavery met its Lincoln; the Know Nothings were swept into history’s dustbin; and once Pearl Harbor was attacked, even Ford and Lindbergh joined the fight against fascism (literally–Ford hired Lindbergh as a consultant at Willow Run, which was making bombers).
As ugly as Trump’s historical analogs were, they didn’t do well in national elections. The Know Nothings did elect a bunch of congressmen and eight governors in the 1850s, but they didn’t survive the Civil War. Father Coughlin endorsed the Union party’s William Lemke for president in 1936; despite his millions of dedicated listeners, Lemke got less than 2% of the vote. As dangerous as Coughlin and Lindbergh were, as pro-Nazi and anti-Semitic as many of the America Firsters were, they couldn’t stop either FDR or America’s entrance into the war. What’s scary about Trump isn’t his racist demagoguery per se–we’ve seen his like before, they show up every 30 years or so, usually at times of economic stress and social change. What’s scary is how deep his support may run during this particular cycle. That’s an open question and one that history can’t provide an answer to.