WASHINGTON – As the dust clears from the final Republican presidential debate before the holiday break, there’s still no better indication of what the GOP establishment intends to do about Donald Trump’s hijacking of the party.

The celebrity billionaire, under heavy bombardment especially from the fading early-book favorite Jeb Bush, walked off the Las Vegas debate stage Tuesday night relatively unscathed. All his rivals, meanwhile, flailed about in their efforts to be the prime alternative to Trump in their prayerful hope that he will somehow be derailed.

Bush did his best by hammering at Trump as “a chaos candidate” who would be “a chaos president” and not “the commander-in-chief we need to keep our country safe.” Trump simply swatted him away, calling his candidacy “a total disaster” and dismissing him as “a very nice person” but “we need toughness.”

For all of Bush’s harsher words than in previous debates, his demeanor again conveyed minimal fire. Trump has described him as having “low energy,” not conducive to success in the theater of political debate.

His previous service as a two-term Florida governor has not helped him much, nor has similar service substantially benefited two sitting governors, John Kasich of Ohio and Chris Christie of New Jersey, as establishment contenders.

Christie was restored to the main debate stage on the basis of slightly improved poll numbers in the New Hampshire primary campaign.

He invoked his experience as a federal prosecutor in New Jersey after the 9/11 attacks to set himself apart from non-politician outsiders Trump and retired neurosurgeon Ben Carson, who had profited on a wave of public anger and mistrust toward practicing pols.

Carson has faded as foreign policy experience has emerged as a critical issue in the era of global terrorism. The two latest rising competitors, Sens. Ted Cruz of Texas and Marco Rubio of Florida, have seized the terrorist threat at home to cast Trump as unfit by temperament and experience to lead the country. In the process, they find themselves locked now in an argument about which of them is best qualified to do so.

In Tuesday night’s debate, Rubio attacked Cruz for a Senate vote against maintaining the National Security Agency’s collection and storing of phone metadata as an essential tool for identifying potential terrorists.

Cruz shot back that Rubio’s early Senate proposal of a path to citizenship for undocumented immigrants amounted to amnesty, and he charged Rubio with softness in maintaining national security along the southern border.

Christie at this point sought to play the anti-Washington card against both Rubio and Cruz, butting into their heated exchange.

Talking directly to the television camera, he offered: “If your eyes are glazing over like mine, this is what it’s like to be on the floor of the United States Senate. I mean endless debates about how many angels on the head of a pin from people who’ve never had to make a consequential decision in an executive position.”

Rubio seems torn between pursuing establishment support in the face of Bush’s stall and demonstrating his conservative bona fides in a party that clearly has swung farther rightward.

Christie meanwhile is working to inherit the role of experienced adult in the room that earlier seemed within Bush’s grasp, but appears all but surrendered in light of his lackluster candidacy.

As for Cruz, he showed no compulsion in the final Republican debate of the year to take on Donald Trump, who had recently alluded to him as “a bit of a maniac” in the Senate and also questioned his steadiness to be president. On the debate stage, Trump let Cruz off with a friendly pat on the back, allowing that “he has a wonderful temperament.”

Cruz appears content for now to let nature take its course regarding the Trump phenomenon. In the meantime, he is poised to make his move as the closest to a Trump clone if circumstances offer him the chance to reap the harvest of the political whirlwind his friend Donald has stirred up in the staid old GOP.

Editor’s note: Jules Witcover’s latest book is “The American Vice Presidency: From Irrelevance to Power,” published by Smithsonian Books. You can respond to this column at juleswitcover@comcast.net.