MASTER THESPIAN?

I am fascinated by all the news coverage I have seen today of Republicans scolding Donald Trump. They are using lines like, "You are acting like a racist bigot" or, "You are acting like a fool" or, "You are acting like a maniac." What do they mean "He is acting like"?  He is all those things.  There is no acting involved here. Are the Republicans trying to salvage their party from this destructive force by suggesting he is acting like something he really isn't. Is it like "Sir Laurence, you are acting like Richard III?"