(NewsNation) — The candidates participating in the fourth GOP presidential debate will be former New Jersey Gov. Chris Christie, Florida Gov. Ron DeSantis, former U.N. Ambassador Nikki Haley and entrepreneur Vivek Ramaswamy.

To qualify, candidates had to get at least 6% in two national polls or 6% in one national poll and two early-voting states, which include Iowa, New Hampshire, South Carolina and Nevada.

Candidates also needed to obtain at least 80,000 unique donors with at least 200 from 20 states and U.S. territories. They are also required to sign a loyalty pledge, promising to support the eventual nominee.

The field has narrowed considerably from the field of eight candidates in the first as candidates have suspended their campaigns or failed to qualify.

Seven GOP hopefuls have suspended their campaigns, including former Vice President Mike Pence and South Carolina Sen. Tim Scott.

Former President Donald Trump remains the front-runner in the race, but has not taken part in any of the debates, which he has referred to as a waste of time. Trump has also refused to sign the loyalty pledge. He is reported to be planning to attend a fundraiser during the debate.

While Trump holds a wide lead, DeSantis and Haley have been jockeying for second place, followed by Ramaswamy and Christie.

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