GOP Debate Analysis: New Fights Emerge as Leading Candidates Try Ignoring Donald Trump

The most tense exchanges pitted Ted Cruz against Marco Rubio.

“We are now at a time where we need more tools, not less tools,” Rubio said. Later, he added: “You can’t carpet-bomb ISIS if you don’t have planes and bombs to attack them with.”

Cruz accused Rubio of distorting his record, and -– a harsher charge –- empowering the Obama administration’s mission.

“Let's talk about how we do this and not which bill which these guys like more. People don't care about that,” Christie said.

The anti-Trump charge was left mostly to Bush, whose migration away from center stage has been accompanied by a desire to fight with the man who still occupies it. Bush attacked Trump for a lack of “seriousness,” noting snidely at one point that he was giving him “a bit of your own medicine.”

“Donald is great at the one-liners. But he’s a chaos candidate. And he’d be a chaos president,” Bush said, in a line worked up sufficiently in advance so that his campaign had a Website with that label ready to go.

Trump brushed the attacks aside, taunting Bush over his poll numbers and with now-familiar rejoinders.

“I know you’re trying to build up your energy, Jeb, but it’s not working,” he said.

“You started off over here and moving over further and further,” Trump said later, referring to Bush’s position on the stage. “Pretty soon you’re gonna be off the end.”

The last Republican debate of the year left the GOP where it’s been at the start of this wild, six-month run. Trump may fade, but it looks increasingly likely that it won’t be what the other candidates say about him that makes it happen.

Toward the end of the debate, Trump even felt generous toward Cruz –- now his closest rival in Iowa, and perhaps nationally.

“He has a wonderful temperament. He’s just fine – don’t worry about it,” Trump said. “You better not attack.”