The Iowa caucuses take place on Jan. 15, and it was clear from Wednesday's contentious interactions that we're getting down to the wire now.

At this point in the race, DeSantis and Haley are best positioned to grab the mantle of "Trump's main opponent," so it was no surprise to see them take big verbal swings at each other over and over on the stage. However, each candidate needs to attract both primary voters who don't support Trump and some of the former president's supporters, a difficult challenge. And with Trump leading by around 25 points in both Iowa and New Hampshire polling, changes at the margins aren't enough.

From that perspective, DeSantis made the case that he's got a conservative track record full of election victories and policy wins. Haley, meanwhile, spent much of the debate on the defensive, but she argued for an assertive foreign policy, greater immigration restrictions and reduced regulations to spur home building.

Their rhetoric may win over a few voters who aren't in Trump's camp, although Christie's showing probably satisfied his small anti-Trump block of supporters. But did any of this convince some of Trump's supporters to break with the former president? Probably not many.

That's a big problem for DeSantis and Haley -- they not only need to gain, they also need Trump to seriously lose ground.

-Analysis by Geoffrey Skelley of 538

This was a feisty debate with a lot of one-on-one clashes, like between Christie and Ramaswamy. But I think it was also largely a continuation of what we’ve seen in previous debates. Haley stuck with the approach that has served her well so far. Ramaswamy was aggressive, perhaps to the point of being abrasive. Christie came out swinging against Trump and didn’t seem to care that it was unpopular. As a result, I’m expecting that this debate won’t change anything about the race. But we’ll see for sure on Thursday, when we get the results of our poll with The Washington Post and Ipsos, in which we’ll ask Republicans voters who won and lost.

-Analysis by Nathaniel Rakich of 538

With a small debate stage on Wednesday, there was much less crosstalk and arguing than in past faceoffs -- but that doesn't mean there was none.

Ramaswamy, who has described himself as the candidate who embraces a disruptive (even provocative) style on stage, got into his share of back-and-forths during the debate and ended up with the most approximate speaking time, according to ABC News' count.

DeSantis trailed very closely behind, and then Haley and Christie were close together in their amounts -- but with more than four minutes less, each, than Ramaswamy and DeSantis.

These totals include time when the candidates talked over one another.

-ABC News' Hajah Bah

Haley, in her closing statement, said America under the Biden administration was a country “in chaos.”

But -- “that’s what Donald Trump gives us,” she said. “My approach is different: no drama, no vendettas, no whining.”

The only candidate to serve in Trump’s White House, Haley has since sought to distance herself from the former president while praising his term in office.

-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