Almost anybody at the presidential podium would introduce and defer to his expert on the subject, when asked a difficult technical question. Not Trump. It's not a President's job to answer difficult technical questions, unless somebody asked Jimmy Carter a question about nuclear reactors. Ask Biden about a virus, and he would have his HHS or infectious disease expert like Fauci answer. And then not contradict him in the next sentence.

Trump is almost unique in this sense. He's actually told us again and again that he knows more on every subject than the experts. That's a very dangerous delusion for anybody in power to have.