evidence: Many chief executives have failed, in one way or another, to live up to the demands of the job, or to competently discharge them. But historians now tend to agree that our worst presidents are those who fall short in the second part of their pledge, in some way endangering the Constitution. And if you want to understand why these three failures make Trump the worst of all our presidents, the place to begin is in the basement of the presidential rankings, where dwell his rivals for that singular dishonor. [...] 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. [...] There are many verdicts on Donald Trump still to come, from the Senate, from juries of private citizens, from scholars and historians. But as a result of his subversion of national security, his reckless endangerment of every American in the pandemic, and his failed insurrection on January 6, one thing seems abundantly clear: Trump is the worst president in the 232-year history of the United States.