Gail Collins: Bret, I really want to talk with you about the presidential debate and, um, regular politics, but first — attempted assassination. Bret Stephens: This is definitely the wrong kind of “déjà vu all over again,” to borrow a phrase. Gail: So depressed that we live in a world in which “but first — attempted assassination” is not really a surprise opening. Story for me is mostly about our dreaded gun culture, but let me open it up for you. Bret: Obviously,...