Washington Donald Trump drew boos from religious conservatives Friday after he called Marco Rubio a "clown" and attacked him on immigration.<br />"You know there's this clown Marco Rubio, I've been so nice to him," Trump said at the Family Research Council's Values Voter Summit in Washington, D.C.<br />"If there's a debate tomorrow, Donald Trump is still front and center," Trump executive vice president Michael Cohen told CNN's Alisyn Camerota on "New Day."<br />Trump and Rubio have been taking shots at each other this week, with the latest hit landing Thursday on Fox, where the Florida senator said Trump is "very thin-skinned, obviously.<br />Rubio has been gaining steadily in national polls, along with former Hewlett-Packard CEO Carly Fiorina, while Trump's lead has been slipping a bit since the second Republican debate.
