In the upcoming fourth Republican presidential debate, only four candidates will take the stage at the Moody Music Hall at the University of Alabama in Tuscaloosa. Notably, the current GOP front-runner, Donald Trump, will be absent for the fourth consecutive debate.

To qualify for the event, candidates needed a minimum of 6% support in two national polls or 6% in one national poll, along with two polls from early-voting states. These states include Iowa, New Hampshire, Nevada, and South Carolina, and all qualifying polls had to be approved by the Republican National Committee (RNC). Additionally, candidates were required to secure at least 80,000 unique donors, with a minimum of 200 from 20 different states or territories. A pledge to support the party's eventual nominee was also part of the qualification criteria.

Here's a brief overview of the candidates who will be participating:

1. Ron DeSantis: Initially considered a top rival for Donald Trump, DeSantis has faced challenges, including staff departures from his super PAC. While he has been in a distant second place to the front-runner, DeSantis has been actively campaigning in Iowa, a critical battleground for his rivalry with Trump.

2. Nikki Haley: Benefiting from increased attention, particularly following the campaign's focus on foreign policy post-Hamas' attack on Israel, Haley aims to continue this momentum in the fourth debate. The exchange of verbal jabs between Haley and DeSantis may also escalate during the event.

3. Vivek Ramaswamy: As a political newcomer and the youngest GOP hopeful, Ramaswamy has faced criticism for his lack of experience. Despite actively participating in numerous events, especially in Iowa, he has struggled to gain significant traction. Ramaswamy had notable clashes with Haley in previous debates, and further interactions are expected.

4. Chris Christie: Positioning himself as the most vocal critic of Trump in the 2024 race, Christie emphasizes his willingness to directly confront the former president. With Trump absent from the debates, Christie has continued to address him, even coining the nickname "Donald Duck" in September if Trump continues to skip debates.

5. Donald Trump: The current GOP front-runner will not be participating in his fourth straight debate. Instead, Trump opts for a closed-door campaign fundraiser in Florida, deviating from the trend of holding counterprogramming events or attending debates.

The smaller candidate lineup sets the stage for a focused and potentially intense fourth Republican presidential debate.