In his new role as Donald Trump’s chief adversary, former Republican presidential nominee Mitt Romney has turned his alarm-fueled message into a robocall on behalf of struggling GOP contender Sen. Marco Rubio, NBC News has confirmed. Romney’s warning is coming to a phone near you in four states voting Tuesday: Michigan, Idaho, Hawaii and Mississippi. ... In the call, which was first reported by the New York Times, Romney notifies listeners that he is calling for Rubio and asks them to choose “a candidate who can defeat Hillary Clinton... A source close to Romney told NBC News Monday that the...