Charlie Kirk took his seat underneath a tent that said Prove me wrong. I wedged myself into the crowd at the University of Montana, next to a cadre of middle-aged men wearing mesh hats. A student standing near me had on a hoodie that read Jesus Christ. It was late September, and several hundred of us were here to see the conservative movement’s youth whisperer. Kirk, the 31-year-old founder of Turning Point USA, was in Missoula for a stop on his “You’re Being Brainwashed Tour,” in which he goes from…