Mitt Romney "really needs to be quiet and go away" regarding Donald Trump and his tax returns, presidential historian Craig Shirley toldon Thursday."There's nothing legal there," Shirley said in an interview with "The Hard Line" host Ed Berliner on whether Trump not releasing his taxes disqualified the developer from the presidential sweepstakes."The American people have a unique way of determining what is disqualifying and what is qualifying," he added. "The only qualifying is that you're 35 years of age and a natural-born American."Other than that, the American people make the decision — not Mitt Romney."Watch Newsmax TV onandGet Newsmax TV on your cable system —