Millions of potential Republican voters will tune in for the debate, but another key audience — particularly for Haley and DeSantis — are the influential voters who have stayed on the sidelines, watching whether one contender can show the ability to beat Trump at a time when he is leading the field by an average of 50 points.

DeSantis and Haley have been engaged in a fierce tussle for second place, and a key poll recently showed the former South Carolina governor pulling even with DeSantis in Iowa, the state his advisers see as the linchpin in his path to victory.

DeSantis was once viewed as the most formidable challenger for Trump — but he has lost that luster as his campaign has struggled with overspending, staff shake-ups and refining a message that failed to connect with many GOP voters.

Look for DeSantis to use the debate stage to try to show voters that he is the tougher adversary for Trump in the early contests next year.

Haley and Pence, two more traditional foreign policy hawks, tangled with Ramaswamy in the two previous debates over his suggestion that the United States should eventually phase out aid to Israel, cut aid to Ukraine and focus on more pressing problems at home. Those exchanges were combative even before Hamas launched its surprise attack on Israel on Oct. 7.

Haley will be looking to draw out those foreign policy contrasts with both Ramaswamy and DeSantis, whose views have often tracked with the more isolationist tendencies of Trump’s supporters.

On Tuesday, Ramaswamy announced that any potential appointee in his administration would have to sign a “No to Neocons” pledge.

Ramaswamy said voters interested in “20 more years of endless wars” should choose another candidate and that he was the choice for voters who want “to stay out of no-win wars and make America stronger at home.”

Policy toward China has become a key flash point in the Haley-DeSantis competition. The outside groups aligned with Haley and DeSantis are using ads to try to paint their respective rivals as too cozy with China in their dealings with that nation as governors. Opposition research and a flurry of falsehoods are flying in both directions, and you can bet both candidates will work those attacks into some of their answers on Wednesday night.

A recent campaign ad by SFA Fund, a super PAC backing Haley, charged that DeSantis voted to “fast-track Obama’s Chinese trade deals” — a claim that The Washington Post’s Fact Checker said earned four Pinocchios.

On the other side, Never Back Down, the super PAC backing DeSantis, suggested in a recent ad that Haley allowed a Chinese company to “get dangerously close” to a U.S. military base — calling her “too dangerous to lead.” The Washington Post’s Fact Checker deemed that ad as a serious stretch that earned Three Pinocchios. As foreign policy takes central stage Wednesday night, expect to see clashes on that topic.

Earlier this year, many Trump foes had hoped that his campaign would falter under the weight of four indictments and his mounting legal bills.

Instead Trump has bolstered his lead over his rivals while using every possible opportunity to portray himself to his supporters as a victim of an unfair legal system. After his contentious day in a Manhattan courtroom on Monday, he sent repeated fundraising solicitations to fill his campaign coffers.

But Trump rivals such as Christie say they believe that Trump’s legal troubles will look like a greater liability to Republican voters who are worried about beating President Biden as the primaries draw closer.

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• HALEY SLAMS RAMASWAMY OVER TIKTOK TIES TO CHINESE GOVERNMENT

• IS THE SURGE OF REPUBLICAN CANDIDATES A SIGN OF AMERICA'S CONSERVATIVE SHIFT

Others like Haley have argued that the former president’s legal problems will be “a distraction” next year when Republicans are trying to defeat Biden. Trump may have brought his campaign into the courtroom in New York this week, but rivals will make sure voters are reminded of the trouble those legal challenges could present for Republicans next year.

The debate will take place at the Adrienne Arsht Center for the Performing Arts of Miami-Dade County and air from 8 p.m. to 10 p.m. Eastern time on NBC News platforms. It will also be live streamed on Rumble.