Chris Christie plays down risk to Republicans if Trump loses primary but won't leave the race

Republican presidential candidate Chris Christie on Sunday sought to play down the potential consequences if rival Donald Trump loses the 2024 primary race but refuses to concede -- or even keeps running as a third-party candidate.

"No one will expect him to concede. He hasn't conceded the 2020 election. Who cares," Christie, a former governor of New Jersey and a Trump supporter-turned-critic, told ABC "This Week" co-anchor Jonathan Karl.

While Trump maintains a huge lead in national polling of Republican primary voters, he is in a slightly weaker front-runner position according to surveys in Iowa and New Hampshire, the first two states to vote, where Christie and other challengers are hoping for an upset.

Pressed by Karl on how Trump's continued presence in the race could be an ongoing problem if he loses -- like if he contests the results or runs third-party -- Christie dismissed that notion, arguing that at that point, "the public en masse will begin to ignore" the former president because of his repeated defeats at the ballot box.

"I think he'll go back to Mar-a-Lago. He'll continue to carp and moan and complain and say we don't deserve him," Christie said. "Anything that gets him out of this race and keeps him out of the White House is fine by me."

Christe's reaction comes as ABC News has learned Americans for Prosperity Action -- an advocacy organization backed by Republican billionaire Charles Koch and his allies -- has plans to endorse an alternative candidate to Trump with the Jan. 15 Iowa caucus now just 50 days away.

With an estimated $70 million on hand to pour into the effort to defeat the former president, Americans for Prosperity also has research that suggests "as many as 75% of Republicans just might be open to a Trump alternative if they think that that person can win," ABC News Political Director Rick Klein told Karl on Sunday.

Trump has so far commanded the Republican field, but Klein said his comparatively weaker early state polling could give other candidates hope that "once people start to engage," there's a chance of eating into his lead.

Christie echoed those sentiments on Sunday, telling Karl that he believes he will be the candidate "who surprises everybody" in New Hampshire, where he has spent significant time campaigning.

"I think people are just starting to engage, even in a place like New Hampshire. You know, I really see people now finally starting to dig in, figure out who they think is saying the things that they want to hear and telling the truth to the voters of New Hampshire," he said.

Christie has pitched himself as the loudest Trump detractor in the GOP primary field. Trump has fired back at Christie, labeling him a "failed" candidate and governor

Christie said on "This Week" that he expects to expand his campaign to South Carolina and Michigan, two of the next voting states in the primary, where he believes he could do "quite well" even as polling shows he has yet to breakthrough in either place.

"Right now, with 58 days to go until the New Hampshire primary, we are going to focus most of our time and energy on the state of New Hampshire," he said.

But with other contenders still in the race, including former U.N. Ambassador Nikki Haley and Florida Gov. Ron DeSantis, Karl asked if this environment is "exactly how Trump wins," by splitting the vote among his opposition.

Christie said that instead of attacking each other, the remaining candidates should all be focusing their fire on Trump.

"If all three of us would go after Donald Trump, well then the most credible amongst the three of us in terms of those critiques would wind up winning this primary, I believe," Christie said.

"I think we need to focus on who's in front here, who's bad for our party, and who would be bad for this country," he continued. "And in my view, that's Donald Trump and we need to go directly at him."