FoxNews will be hosting the next Republican debate tonight at 9:00 p.m. Eastern. As everyone knows by now, the debate will be unusual in that the current front-runner won’t participate, and will instead have his own event of some sort scheduled at around the same time. That almost certainly means that the debate audience will shrink by quite a lot, which is why FoxNews has been so desperate to get Trump to reconsider. Trump’s absence won’t just shrink the audience, but it will also make the debate a less consequential event just a few days ahead of the Iowa caucuses. Many people have reasonably speculated that Trump is ducking the debate so that Cruz can’t inflict any damage on him before Monday, and it’s true that Trump has little to gain by attending.

The debate is important for Cruz, since he probably needs an excellent performance to take back the lead in Iowa, and it may be even more so for Rubio. Rubio needs some momentum coming out of Iowa, so a poor or mediocre showing tonight could be a serious problem for his campaign. The non-Rubio “establishment” candidates just need to have an error-free night, since none of them is competitive in Iowa anyway. As in the last debate, Bush, Kasich, and Christie will be hoping to trip up Rubio and weaken him ahead of New Hampshire, and Cruz has every incentive to try to do the same. Even though Cruz is the highest-polling candidate on the main stage tonight, more of the candidates will see an advantage in targeting Rubio than going after Cruz. Carson will also be present. I suspect the debate will be even less focused on policy than the last one, and I assume it will be more acrimonious than ever.

Rand Paul has been brought back into the main debate, which will add to Rubio’s difficulties. I expect Paul will cause some headaches for all of the hawkish candidates, but he’ll likely use Rubio as a foil for his arguments as he has done in the past. Tonight’s event gives him a final opportunity to make a favorable impression on the main stage before the first contest. Paul’s campaign has confidence that they have a solid ground game in both Iowa and New Hampshire, and a good debate performance could help inspire a better-than-expected result for him.

As usual, I will be covering the debate on Twitter (@DanielLarison).