Donald Trump will lose his zest for campaigning as it gets harder and drop out before Iowa, and Republicans eventually will nominate a presidential candidate who has previously held elective office, a senior strategist for Mitt Romney’s 2012 presidential campaign said Monday. Speaking at the Clinton School of Public Service, Stuart Stevens said that running for president is “the least enjoyable experience that adults voluntarily enter into.” In August, he wrote in The Daily Beast that Trump wouldn’t even run in order to avoid being tagged a loser, and he still believes that will happen once running for president stops...