In closing remarks, Christie contended that Trump will be a felon by November 2024 given the four criminal cases against him. He has pleaded not guilty.

"I want you to all kind of picture in your mind Election Day. You'll all be heading to the polls to vote. And that is something Donald Trump will not be able to do, because he will be convicted of felonies before then and his right to vote will be taken away," Christie said.

The statement drew loud boos from the crowd -- a recurring theme for Christie's comments about Trump.

"You can boo about it all you like and continue to deny reality. But if we deny reality as a party, we're gonna have four more years of Joe Biden," Christie said.

-ABC News' Meredith Deliso

As she called for a ban on TikTok, Haley said, “We now know that 50% of adults 18-to-25 think that Hamas was warranted in what they did with Israel. That’s a problem.”

When PolitiFact checked the polls in early November, we found a Harvard-Harris survey that found 48% of American 18-to-24 year olds said they sided with Hamas after the Oct. 7 terror attack on Israel that Israeli officials say killed 1,200 people.

However, that poll was based on a subsample of 199 people with a large margin of error.

The responses to other questions were also inconsistent with that view. Respondents in the subgroup said, by 2-1 margins, that Hamas’ Oct. 7 action "was a terrorist attack"; that the attacks "were genocidal in nature"; that Israel has "a responsibility" to retaliate "against Hamas terrorists"; and that Hamas "is a terror group that rules Gaza with force and fear and is not supported by them."
Three other polls found lower rates of support for Hamas, we reported.

-Analysis by Katie Sanders of PolitiFact

Recent polling found that Americans believe Taiwan is an ally and important to U.S. security. In September, the Chicago Council on Global Affairs found that 65% of Americans felt that the country's security relationship with Taiwan does more to strengthen national security than weaken it. And large majorities backed supporting Taiwan in different ways if China were to invade the self-governing island, save sending U.S. forces to the theater. Overall, 78% of Americans would want the U.S. to airlift food and medicine to Taiwan, 75% would want economic and diplomatic sanctions on China and 62% would want the U.S. to send more arms and military supplies to Taiwan. But in terms of military intervention, half said they would support using the U.S. Navy to break a blockade, while 56% opposed sending U.S. troops to Taiwan.

--Analysis by Geoffrey Skelley of 538

Ramswamy defended his position that the U.S. should arm the Taiwanese people with assault-style weapons, despite a Taiwanese zero-gun policy, and added the U.S. should “for the foreseeable future” promise to defend the self-governing island from China, which claims it as its own.

Ramaswamy drew a contrast with DeSantis, who hewed closer to the strategic ambiguity behind America’s longstanding deterrence posture. Haley, separately, said America must continue to defend Ukraine as a signal to Beijing that it can’t attack Taiwan and said the U.S. should not depend on China for national security.

Christie said he would engage militarily if Taiwan is invaded by China.

-ABC News’ Chris Boccia

Can anyone take down Haley? According to 538’s polling with The Washington Post and Ipsos, Republican primary voters have responded favorably to each of Haley’s first three debate performances, and it’s probably not a coincidence that she’s been rising in the polls at the same time. But that could put a target on her back on Wednesday -- and it’s possible that her momentum will stall if she’s perceived to have a bad performance.

Will anyone go after Trump? So far, the debates have mostly consisted of the candidates on stage attacking each other. But that’s an odd strategy considering that their biggest obstacle to the nomination is Trump. In fact, he’s above 50% in 538’s national polling average -- meaning that even if another candidate consolidates all of the non-Trump vote, Trump would still be ahead. That means that someone is going to have to peel support away from Trump in order to win the nomination -- and one way to do that is to attack him in the debates.

Who will perform best on the economy and immigration? According to the latest 538/Washington Post/Ipsos poll, 52% of likely Republican voters said getting inflation or costs under control was one of the top three issues in determining their primary vote; 41% said controlling immigration was one of their top three issues. These will probably be the most important segments to watch at the debate then: If a candidate really aces a question on inflation or immigration, that could go a long way.

Will anyone watch? The ratings have been falling with every debate: While the August faceoff garnered 12.8 million viewers, the September one got 9.5 million and the November one got only 7.5 million. And only 26% of the respondents to our 538/Washington Post/Ipsos poll said they were very likely or absolutely certain to watch the fourth debate. Obviously, the fewer people who watch the debate, the less anything that happens on stage will matter.

-Analysis by Nathaniel Rakich of 538