President Trump effectively claims that he is entitled to preemptively kill suspected drug traffickers anywhere on earth, or at least in the Western Hemisphere. The U.S. military has killed hundreds of people in its attacks on suspected smugglers’ boats off the coast...

The men who wrote the Fourth Amendment had watched a government treat a population as a thing to be catalogued. They had lived under writs of assistance — general warrants that let a customs officer search any house, any ship, any person, on no suspicion at all. So...