Vice President JD Vance keeps trying to straddle a bright moral line — with predictably disastrous results. The veep’s appearance before the Republican Jewish Coalition in Las Vegas on Monday was highly anticipated because of his increasingly tenuous relationships with both the group’s direct constituency and the pro-Israel, evangelical GOP base. Vance’s troubles with both these key communities stem from both his seemingly unbreakable bond with Tucker Carlson — the country’s leading antisemitic advocate — and his indulgence of a wide range of injurious conspiracy theories and tropes. In one particularly notable moment from his December speech before Turning Point...