Kirk, like all victims of gun violence, was someone’s family member — a husband, a father, a son. He was a professed Christian and a provocateur who took his message to places that were often hostile; he welcomed a back-and-forth with those who disagreed with his views. He was a media savant who leveraged his views into the algorithms of young people, particularly men, who have been historically reluctant to engage in politics. Many people who couldn’t have picked Tucker Carlson or Candace Owens out of a police lineup knew Charlie Kirk. Turning Point USA, the political organization he co-founded...