Donald J. Trump said Thursday that transgender people should be allowed to use whatever bathroom they feel most comfortable with — including at Trump Tower in New York. Dipping into a contentious issue by taking a stand many Republicans oppose, Mr. Trump told a town-hall-style event, hosted by NBC’s “Today” show at Rockefeller Center in Manhattan, that when people go to the restroom, they should “use the bathroom they feel is appropriate.” Mr. Trump, the Republican presidential front-runner, was responding to a question about a bill that North Carolina’s governor signed into law last month that bars individuals in the...