It’s hard to pick the low point of a debate that dissolved frequently into incoherent crosstalk and included former vice-president Mike Pence, a Christian conservative who has famously said he would never dine alone with a woman other than his wife, attempting to make a joke about his sex life. (“My wife isn’t a member of the teachers union, but I gotta admit I’ve been sleeping with a teacher for 38 years,” he said.) In a debate conducted not far from Ronald Reagan’s grave, seven GOP presidential candidates shouted and sniped at each other for two hours without producing a…