Tonight I’ll be keeping track of DeSantis, who, despite several campaign shakeups and a steady slide in both national polls and early state surveys remains the second-place contender in the GOP primary, and who will appear at center stage this evening. DeSantis didn’t have a breakout moment last debate, though he may have been hobbled by the embarrassment of his Super PAC publicly releasing his entire debate strategy just beforehand. This time around, he may need to make a larger splash to re-convince voters he’s the best (or only) alternative to Trump. The other candidates are now nipping at his feet — he’s not even polling second in New Hampshire and South Carolina anymore — and if he becomes just another member of the pack he could lose whatever luster he has left. He’s already (started taking shots at Haley)[], who had one of the better-reviewed first debate performances and who has seen some movement in the polls. With seven candidates on stage, he’ll have limited time to make his move. Will he finally go after Trump more forcefully, or does he feel enough pressure from below to focus on Haley and the others?

—Analysis by Jacob Rubashkin, 538 contributor

I'm closely monitoring Vivek Ramaswamy. The self-proclaimed outsider made a big splash during the last debate, garnering more media attention and generating higher Google search interest than his rivals. This triggered speculation that he might experience an upswing in the polls. However, his numbers have exhibited a consistent downward trend over the last month. It's plausible that the very characteristic that initially captivated debate viewers — his confrontational and too-smart-to-be-here style of arguing — may have, ironically, alienated the average Republican voter. I'll be looking for any shifts in his rhetorical approach or substantive positions during tonight's proceedings. Like his fellow candidates, Ramaswamy needs a substantial strategic maneuver to reshape the trajectory of his campaign.

—Analysis by G. Elliott Morris

I’m monitoring Pence tonight, and I’ve got to be honest: I don’t know how much he can do to increase his standing in the primary other than hope that other candidates implode. During the last debate, he had plenty of speaking time and, given Trump’s hatred for his former vice president, a pretty strong reception from the Fox News crowd. But still, nothing substantially changed. Voters expected him to give an average performance, and he pretty much delivered. He’s averaging less than 5 percent in national primary polling.

It’s not clear where Pence has room to grow. He’s better known than any candidate on tonight’s debate stage, and voters seem to have decided how they feel about him. If he’s a second-choice to similar candidates — others who, say, share his dislike of Trump but would nonetheless support him in a general election — Pence could benefit from a smaller field. So, the best thing Pence could do might just be to stay the course, continuing to get enough support to appear on a debate stage and waiting out lesser-known and underfunded candidates.

—Analysis by Leah Askarinam

I’ll be monitoring Haley and Christie tonight, who have taken different approaches to arguing for the Republican Party to move beyond Trump. While Haley has been somewhat critical of Trump, Christie has aggressively gone after him. Not coincidentally, Haley remains relatively well-liked among GOP voters, unlike Christie, who is persona non grata to most. I’m interested to see how Haley will seek to balance criticism (indirect or direct) of Trump with efforts to play to base voters, especially in polls of . As for Christie, I’m watching for how other candidates will use him as a foil to demonstrate their pro-Trump bona fides.

—Analysis by Geoffrey Skelley

The second debate stage will look mostly like the first, as seven of the eight candidates who took part in the initial August debate qualified for tonight’s event. And just like the first debate, front-runner Trump has decided to skip the event, despite having the polls and donors to make it. To qualify, the RNC mandated that candidates have at least 3 percent support in two national polls, or at least 3 percent in one nationwide survey and two polls from separate early states, based on polls conducted since Aug. 1 that met the RNC’s criteria for inclusion. Candidates also had to attract at least 50,000 unique contributors, with at least 200 from 20 different states or territories.

The RNC raised the polling and donor standards for the second debate, which slightly winnowed the list of participants. The new rules raised the level of support candidates needed in qualifying polls from 1 percent to 3 percent, and the number of unique donors from 40,000 to 50,000. Six of the seven qualifying candidates had little trouble meeting these polling and donor thresholds. However, although Burgum had enough donors, he struggled to poll well enough nationally to qualify. It took until the Saturday before the debate for him to get the national poll at 3 percent he needed. Meanwhile, former Texas Rep. Will Hurd and former Arkansas Gov. Asa Hutchinson came up short of qualification, as Hurd lacked sufficient polls and only got to 50,000 donors on Monday, while Hutchinson didn’t have enough qualifying polls or donors.

—Analysis by Geoffrey Skelley of 538