When Donald Trump’s attorney argued that the former president should be immune from any prosecution as long as he wasn’t removed from office over it, the world laughed, but a former prosecutor said Saturday that the argument could have had a purpose. Trump’s attorney specifically claimed that Trump could issue an order to have Seal Team 6 kill his political opponent and, as long as he isn’t impeached over it, he can never be prosecuted. That argument might not be as ridiculous as it sounds when you consider its purpose, according to former Brooklyn, N.Y., prosecutor Charles Coleman. POLL: Shou…