Former Justice Department officials Andrew Weissmann and Mary McCord flattened Donald Trump’s recent claim that, without presidential immunity, presidents like Harry Truman would have been unable to act. Addressing a campaign rally over the weekend in Manchester, New Hampshire, Trump said that presidents would be unable to function without full immunity. “Harry Truman would not have done — Harry Truman would not have done Hiroshima and Nagasaki. Probably ended the war. Probably. I think so. But he wouldn’t have done it. So many things wouldn’t be done,” Trump promised. Want more breaking polit…