It's almost time for the second Republican debate, although we're still waiting to hear who exactly will be allowed on the stage Wednesday night. Just as in the first debate, frontrunner Donald Trump will not be on the stage, not through being disqualified in some way but because he has decided (once again) to stage his own event in an effort to "counterprogram" the Fox debate. Trump has a big problem with the Ronald Reagan presidential library where the debate will be held, but even without that dynamic he still likely would have skipped this one as well. He is -- quite accurately -- figuring that there isn't a whole lot of upside for him showing up, since he is already so dominant in the polling at the moment. So once again we're going to see all the candidates who have yet to truly challenge Trump's standing with Republican voters bickering among themselves.

Even though this is only the second debate, one has to wonder whether anything is going to change as a result. No candidate had a true "breakout moment" in the first debate (no matter what various pundits had to say about it at the time) as shown in the polling. Some marginal changes happened, but there were no giant spikes upwards or downwards. It's impossible to say whether that will hold true again or not, but it does seem to be the most plausible outcome at this point.

The national polling (note: all numbers come from the rolling daily averages at the Real Clear Politics site) stands virtually unchanged over the past month. Trump's numbers came down a bit (from 55.2 percent to 52.7) and then went up to a new high (58.8) before falling back to 57.3 percent. You'll note that all of those numbers are solidly above 50 percent, and Trump is even starting to post individual polls which put him at 60 percent or better.

Ron DeSantis didn't do himself any favors last month, as his poll numbers continued their general downward trend. The day of the debate, DeSantis was at 14.2 percent, then saw his numbers oscillate a bit -- up to 14.9, then down to 12.4 -- before settling in at 13.5 percent. He's still got a firm grip on second place, but if he continues his general slide downwards he'll soon be fighting others for the honor (if his numbers sink down into the single digits).

Vivek Ramaswamy probably made the biggest splash in the first debate, but it didn't translate into a groundswell of support. A lot more people know his name, but that's about it. He has kept his hold on third place (for whatever that's worth), but didn't show much movement. He started at 7.4 percent support, fell back to 6.6 percent, rose to 8.1 percent and then finished at 6.8 percent (a little worse than when he started, in other words). Being brash and mouthy does get you some viewer attention, but it didn't seem to change many people's minds.

The only real movement in terms of standing took place in the contest between Nikki Haley and Mike Pence, for fourth and fifth places. Heading into the first debate, Pence was regularly beating Haley by a few points, but Haley got the only real "debate bump" of anyone, and her numbers climbed above Pence, where she's now beating him by a few points. Haley even got close to Ramaswamy a few weeks back, but never overtook him. At the moment, Haley stands at 5.3 percent to Pence's 4.2 percent.

Tim Scott and Chris Christie remain almost exactly where they were before the second debate, locked in their own struggle for sixth and seventh places. Currently, they are tied at 2.5 percent.

The really big question I have, two days out, is whether anyone else will qualify to appear on Wednesday. Asa Hutchinson and Doug Burgum are both polling below a single percentage point, and part of the entry criteria for appearing was that they had to chart at least three percent in a national poll (which has to be a poll with a methodology that is acceptable to the Republican National Committee). This could keep both of them off the stage on Wednesday. This is by design -- the R.N.C. wanted to avoid having an overwhelming amount of candidates on stage, and at this point anyone who doesn't make it really should think very strongly about getting out of the race. Burgum is trying hard -- I personally saw an ad from him twice in the past day, airing during the Sunday morning political talk shows and during football games. He's got a lot of (his own) money to spend, so this seems like an attempt to get his name before a national audience, but we'll see whether it works for him or not. Neither Burgum nor Hutchinson added all that much to the first debate, so excluding them from the second seems reasonable to me. The next step upwards, for the third debate, will be hitting a threshold of four percent, which could be challenging for Christie and Scott, so it seems like the winnowing process is working as the R.N.C. intended it to.

Of course, the candidates not named "Trump" would all point to the early-state polling, which does show at least some differences from the national polling, and is going to be a big determinative part of the primary race when the votes are cast. In Iowa, Trump is polling below 50 percent, but not that far below. DeSantis is still in second, with around 15 percent, but here Haley has indeed overtaken Ramaswamy, who is now being challenged by Tim Scott. Haley is at 9.0 percent while the other two are at 7.5 and 7.0, respectively. Everybody else is below three percent.

New Hampshire's polling is getting interesting, mostly because here there actually was a notable post-debate spike. Nikki Haley went from polling between three and four percent up to a tie for third place with DeSantis at 9.7 percent. Chris Christie, surprisingly enough, is in second place at 10.0 percent. Christie has focused almost exclusively on the Granite State (largely ignoring Iowa), and it appears his strategy has paid off to a certain extent. Ramaswamy is still in this mix as well, at 9.3 percent. That means four candidates are pulling roughly 10 percent each, while Trump is hovering right around 45 percent.

But the problem still remains -- if all of these candidates stay in the race, they will be splitting the "not-Trump" vote among themselves. And I don't see any of them dropping out before New Hampshire votes, really. Christie, Haley, DeSantis, Ramaswamy, Scott, and Pence will all likely hang in at least until then. Perhaps one or two of them will drop out after dismal showings in Iowa, but it's doubtful. Haley and Scott will both almost certainly stay in until South Carolina votes, where they will likely wind up splitting the not-Trump vote in their home state.

Obviously, there's room for improvement for all of these candidates. Which is why the second debate will likely be a fierce one, because they all have so much at stake. They're all fighting to be the one candidate that all the "not-Trump" voters rally around. But in the end even if one of them does consolidate this demographic behind them, they've still got to slay the dragon that is Trump. Trump is leading the field by more than 40 points right now. For anyone else to have a prayer of dethroning him, they've got to make the case to the voters that Trump is an unacceptible candidate. In the first debate, only four of them really made forays into doing so -- Christie and Hutchinson (who are both running flat-out anti-Trump campaigns) and, to a lesser extent, Haley and Pence. All the others couldn't bear to say a bad word about Trump -- who they are running against and ultimately have to beat, mind you.

Will that change Wednesday night? Christie knows this could wind up being his final debate (although he's got a decent shot at surviving for one or two more, at the least), so he'll be unloading on Trump once again. Hutchinson may not even be allowed on Wednesday's stage. Haley seems to have the most to gain and her strategy of being no-nonsense and realistic about several issues (in contrast to Trump, which she did indeed point out several times).

DeSantis must be getting pretty desperate, so he could make some surprising statements in a bid to stay relevant. Ramaswamy is likely to turn in another completely annoying performance, testing the moderators' patience for people speaking out of turn. Scott was barely a presence in the first debate, so I'd look for him to also try to show some more strength. Pence will likely do his usual schtick, proving once again that Trump erred in his choice of playground insults since Pence is truly "Mister Sanctimonious" almost by nature.

My guess is that almost no matter what happens Wednesday night, the real winner of the second Republican debate will be the man who won't be there. Trump will likely win by default. Even if few people bother to watch his speech to Michigan Union members, Trump will still dominate the debate night. Will anyone actually land a blow on Trump that works? I'd love to see that (my own personal bias showing), but kind of doubt it'll happen. Will any of them effectively disqualify someone else on the stage in the eyes of the voters? That's a little more likely, but such knockout punches are pretty rare.

The one thing I would look for is for the candidates to be a lot more ready for each other this time around. In the first debate, Ramaswamy overwhelmed just about everyone with his manic energy. This time, the others might be a little more prepared to deal with him. DeSantis got off surprisingly lightly last time around, but he still holds onto second place and all the others must be envious of his double-digit polling. So I'd look for him to bear the brunt of a few attacks. Haley is going to be the interesting one to watch, though (for me at least). Unlike most of the others, she did move (modestly) upwards after the first debate. She'll be looking to repeat and enhance that performance, and she's got a surprisingly effective tactic to do so. She is trying to interject some realism to the raging right-wing debates over subjects such as abortion, and she did an admirable job last time of appearing to be "the adult in the room." But because she did see some success with this the first time, the other candidates might have prepared some attacks for her as well, so it'll be interesting to see who goes after her, and how.

The second Republican presidential debate might turn out to be purely academic, of course. Unless Trump's numbers take a deep dive at some point, he looks like he's going to skate away with the nomination no matter what any of the other candidates do or say. Consistently polling above 50 percent could mean that nobody's going to get close and Trump's going to walk away with the lion's share of delegates. He may even effectively wrap up the nomination by Super Tuesday. Everyone on stage Wednesday night will be fighting hard to try to change that dynamic, but they didn't manage to in the first debate so it's more likely than not that the second debate won't change a whole lot either.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant