On Tuesday, as world leaders addressed the United Nations General Assembly, diplomats were lectured by an authoritarian, a torture apologist, a pillage enthusiast, a race-baiter, and a sectarian demagogue. At the U.N., that’s an ordinary day. But this time, the despot, the demagogue, and the war-crimes advocate had something unusual in common. This time, they were all the president of the United States. Most Americans, in both parties, like to think of our country as the good guy.