I knew from the start that it was more of a campaign slogan than a policy proposal. But from that starting point it’s certainly possible to construct a constitutional, effective, fair policy that would severely limit immigration from population that include a disproportionate number of terrorists. It’s not Trump’s job to figure out the details of that; there will be phalanxes of various kinds of experts who will slave night and day to come up with something. The point is his priority is protecting us, not the would-be immigrants.