Donald Trump could win a second term as U.S. president in 2020 against deep opposition from the establishment and the progressive left. A letter from a Trump supporter to the Wall Street Journal (WSJ) indicates why he could win: “I am unalterably supportive, flawed vessel or not. It’s not the man, it’s the resistance that binds us to him.” Daniel Henninger, a journalist at the WSJ, said he receives many letters like this. They are the “voice of resistance h…