Donald Trump pulled off one of the greatest political feats in modern history by defeating Hillary Clinton and the vaunted Clinton machine. The election was a complete repudiation of Barack Obama: his fantasy world of political correctness, the politicization of the Justice Department and the I.R.S., an out-of-control E.P.A., his neutering of the military, his nonsupport of the police and his fixation on things like transgender bathrooms. Since he became president, his party has lost 63 House seats, 10 Senate seats and 14 governorships. The country had signaled strongly in the last two midterms that they were not happy. The...