One day after president Obama took a pot shot at Donald Trump in what appeared to be an escalation in campaigning against the New York billionaire on Hillary’s behalf during a Wednesday PBS town hall, Trump promptly shot back, saying that “this is a president who doesn’t have a clue,” during his rally in Sacramento. “He’s going to start campaigning. Well, if he campaigns, that means I’m allowed to hit him just like I hit Bill Clinton, I guess right…