Updated on November 20 at 2:10 p.m.

Being Donald Trump means, among other things, never backing down and never saying you’re sorry. He is a Mitt Romney book title come to life.

On Thursday, Yahoo News published an interview in which Trump seemed to assent to reporter Hunter Walker’s suggestions of requiring Muslims to register in a database or giving them a form of special identification attached to their religion. Walker wrote, “He wouldn’t rule it out.” Trump’s own comments were much vaguer: “We’re going to have to—we’re going to have to look at a lot of things very closely. We’re going to have to look at the mosques. We’re going to have to look very, very carefully.”

Trump’s defenders, and some folks who also aren’t Trump defenders, felt this was a little unfair. After all, Walker had fed the ideas to Trump. Were they really Trump’s? It doesn’t seem like too much to ask that Trump repudiate ideas like this, but gaffes happen.

Trump demolished that defense Thursday night. He declined the chance to walk back his comments. At an event in Newton, Iowa, NBC asked him whether there should be a database to track Muslims. “There should be a lot of systems, beyond databases. We should have a lot of systems,” he said.