When it comes to musicians taking on Donald Trump, the rock world has definitely taken the lead. It was Bruce Springsteen leading the way last summer with Eddie Vedder joining in. The Dropkick Murphys dropped out of a whole series of concerts due to a promoter’s support of the president. Neil Young has been a long-time critic, too, and so has Tom Morello. There have been more, and it looks like the pressure from the artists — particularly Morello and Young — isn’t going to let up anytime soon. Morello was the most recent to go after Trump and his...