They were describing their experience dealing with kings and people who want to be kings. King is a personality type, not only a role. In more clinical settings they’re called narcissistic sociopaths, which is what Trump has proven himself to be, so that’s why we call him a king. Sometimes their title is “dictator”, sometimes it’s “emperor” or “fuhrer” or “chairman”. In this case his title is “president”, but he acts like a king, so that’s why we say we don’t want kings. This applies equally to wannabe kings.