The gloves were off in last night’s Republican debate. Not so much in terms of the back and forth between the candidates &#8211 they were very polite &#8211 including Donald Trump, but in terms of how America will fight terrorists.

Mr. Trump confirmed that yes, to win the war against ISIS, he would not just go after terrorists, because terrorists don’t care if they die. He would kill their families.

“I would be very, very firm with families and frankly that will make people think,” Trump explained. “Because they may not care much about their lives but they do care &#8211 believe or not &#8211 about their families’ lives.”

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Jeb Bush pushed back.

“This is another example of the lack of seriousness,” he said of Trump.

Rand Paul waved the rule book at him.

“If you are going to kill the families of terrorists, realize that there is something called the Geneva Conventions we’re going to have to pull out of,” he said. “It will defy every norm that is America.”

But Trump was unfazed. To Jeb he said: “Honestly, I think Jeb is a very nice person. He is a very nice person. But we need tough people, we need toughness.”

And to Rand Paul: “So they can kill us but we can’t kill them?”

And that shut everybody up.

Terrorism seems to be changing what’s acceptable. More Americans are seeing collateral damage not as an unintended consequence of war, but as a way to win a war. And if there are any more terrorist attacks between now and next November I’m betting it won’t be just Republicans talking that way.