Well, he could, but he'd definitely end up in prison if not shot by Secret Service agents.
Robert De Niro was Jimmy Kimmel's first guest in the post-election world we now live in and to say he was in a less than pleasant mood on the show would be an understatement.
Having previously announced that he wanted to punch Trump in the face, De Niro had to face the fact last night that he can no longer do so since he's now President-Elect of the United States. And that does not a happy actor make.
Sad De Niro is not something we want to see again. It's just too depressing to watch.