Whether it's enough to sink The Donald has yet to be seen — plenty of "fatal" moments in Trump's presidential campaign have proven to be anything but.

But when Trump, at a town hall in New Hampshire, didn't bother to correct an audience member who told him "We have a problem in this country. It's called Muslims. We know our current president is one. You know he's not even an American," the real estate mogul and reality show host fell short of Chris Christie's definition of a leader.

The New Jersey governor walked a fine line on the Today show Friday, stopping just short of criticizing Trump while making it clear his own response would have been markedly different.

"I wouldn't have permitted that," Christie said. "I would correct him. I'd say that the president's a Christian and he was born in this country. Those two things are self-evident."

"I think you have an obligation of a leader to do that," Christie said.

That's not the route Trump went. He told the questioner: "We are going to be looking at a lot of different things. And a lot of people are saying that and a lot of people are saying that bad things are happening out there. We are going to be looking at that and plenty of other things."

Christie said Trump must decide "how serious a candidate he wants to be."  But he also said he wouldn't "lecture" Trump about how to conduct his campaign.