What to watch for during tonight's GOP debate:

Workers stand in at the candidate’s podiums on Nov. 9, 2015, in preparation for Tuesday’s Republican debate in Milwaukee. (Morry Gash, AP)

After the Republicans' debate Tuesday night in Milwaukee, they’ll meet just twice more before the first votes for president are cast Feb. 1 in Iowa. That means precious little opportunity for front-runners Donald Trump and Ben Carson to quash the competition, for those in the middle tier, like Sens. Ted Cruz and Marco Rubio, to make a breakthrough, and for those sinking fast, like Jeb Bush, to show some spark.

Good news: Like CNN, Fox Business will be streaming the debate online for free. You don't need to have a cable login — you can just log on to Fox Business' website and stream the debate live on Tuesday night. Additionally, Fox Business announced Thursday that it would be streaming the debate through providers that don't generally feature the channel, including DirecTV and Mediacom.

Here our five things to watch for during tonight's republicans' debate:

Ben Carson under the microscope: Carson is getting a crash lesson on the scrutiny that comes with being a presidential frontrunner. The political neophyte has confronted a series of questions about his past in recent weeks, as he's pulled slightly ahead of Trump in some polls.

How will Rubio defend himself? Rubio is the candidate to watch these days. His poll numbers are on the rise, he's picking up key endorsements, and he's had several strong debate performances -- all while his one time mentor, Jeb Bush, is struggling to turn around a flailing campaign.

Jeb Bush's latest reboot: Bush's debate performances have been so lackluster this cycle that he's enlisted professional help. Describing the advice he's received from his newly hired media coach, Bush said earlier this month: "He's telling me to be me. He's telling me to own what I believe." But the precise dilemma for Bush when he walks onto Tuesday's prime time stage is whether he's better off being himself -- the former Florida governor is a self-described introvert and uncomfortable in the role of attack dog -- or trying to show that he can be an aggressive and combative candidate.

Chris Christie at the kids' table: For the first time, Chris Christie will get to stand in the middle of the debate stage Tuesday. Unfortunately, that moment will be at the "undercard" debate. The New Jersey governor was bumped off of the prime time debate, relegated to an earlier event featuring three other lower tier Republicans: Mike Huckabee, Rick Santorum and Bobby Jindal.

Moderators in the spotlight: It's not just the candidates that will feel the heat Tuesday --- there's also a lot riding for the moderators. CNBC, the host of the last GOP debate, found itself on the receiving end of a litany of hostile criticism. The Fox Business and Wall Street Journal moderators hosting Tuesday's event are likely to be sensitive to the concerns raised last month and aware that any line of questioning perceived as being in poor taste could once again draw fierce blow back.

The next democratic party debate will be on Nov. 14, 2015 8 p.m. CST at Drake University Des Moines, IA, moderated by CBS News/KCCI/ The Des Moines Register.