Trump’s heartless and incompetent approach to immigration, his use of tax policy to punish states that didn’t vote for him, his diversion of public funds to properties owned by him and his family, his impulsive and self-defeating approach to trade, and his petulance toward traditional allies assured on their own that he would not be seen as a successful modern president. But those failures have more to do with the first part of his oath. The case that Trump is not just the worst of our modern presidents but the worst of them all rests on three other pillars, not all of which have a Nixonian parallel.