Omar Mateen pledged allegiance to ISIS while he opened fire on the Pulse nightclub in Orlando last weekend, proving his attack was borne out of radical Islam. Yet, if you ask some bystanders in Brooklyn, they’ll tell you the gunman’s rampage had nothing to do with religion. That’s what filmmaker Ami Horowitz found when he asked New Yorkers who was to blame for Sunday’s stark death toll. “I don’t think it had much to do with Islam, to be honest,” said one Brooklynite. “I don’t think it was a terrorist,” said another. Republicans and guns played a much larger role in...