GOP contenders at the Las Vegas debate on Oct. 18. (Ethan Miller/GETTY IMAGES)

Here are five key questions:

1. Will a moderator or candidate raise the Cain allegations? Dubbed “Your Money, Your Vote,” Wednesday’s debate is supposed to be exclusively about the economy, but perhaps it depends on the definition of the word exclusively.

Sharon Bialek’s allegations of sexual advances by Herman Cain, along with other accusations, have dominated headlines in recent days and have threatened to weaken Cain, one of the leading contenders in the presidential field.

Most of the candidates have addressed the allegations, in varying degrees (Romney made the strongest statements, calling the allegations disturbing and serious) but this debate will draw millions of likely Republican voters of the Rockefeller variety.

Polls show Cain is extremely-well liked by GOP voters, even those who are supporting other candidates. So it could be risky for any of his rivals to highlight the sexual harassment flap: Alienate Cain. Alienate his increasingly fervent supporters. And since Cain so adamantly brings up race, let’s do that too: Being the first to ditch the black guy who claims he is a target of liberals because he is black might not go over so well, even given Cain’s struggles.

But taking Cain down is the easiest way that candidates like former senator Rick Santorum and Rep. Michele Bachmann (R-Minn.) — both seeking the conservative tea party vote — can gain some traction and start making some noise.

2. How will Romney navigate his auto bailout position?

Over the last three years, as presidents Bush and then Obama offered federal money to help rescue the auto companies, Romney has given a series of statements that don’t make clear what exactly he would have done as president or whether he supports the policies that Obama adopted in restructuring Chrysler and General Motors. (The New Republic’s Jonathan Cohn does an excellent job of summarizing Romney’s positions.)

Will Romney say he supported the bailouts, which are very popular in Detroit, or that he opposed them?

Will his rivals press him on the issue and look for a vulnerability, reminding Romney of his “Let Them Go Bankrupt” editorial?

So far, Romney’s Republican opponents have struggled to land a strong blow against the former governor for seeming to shift his positions with the political winds. There hasn’t been a soundbite flip-flopping moment that could permanently damage Romney’s campaign yet and perhaps the auto bailout could provide that clip.

3. Will one of the Republicans propose no taxes on any American ever? From optional flat taxes (Texas Gov. Rick Perry) to zero tax on companies that hire employees living in the U.S. for new manufacturing jobs (Santorum), the Republican candidates are in a race to declare how low they can go in reducing taxes for individuals and corporations. They have argued that their tax plans won’t balloon the budget deficit (though evidence suggests otherwise) and they have argued that they would cut federal spending sharply, and that the cuts would result in broader economic growth.

(Yet prior years suggest this theory may not work.)

This is the first debate since Perry announced his flat tax plan and started carrying around a post card in his jacket pocket to indicate the simplicity of his plan. Wednesday could offer the candidates a chance to illustrate which idea would cut taxes the most and the CNBC moderators can in turn say not so fast.

4. Can Rick Perry use this debate to vault himself back to the front of the field? Probably not. But this is the obligatory question that is asked before every debate, so get used to it. Really, though, this is by now a settled matter. Perry has openly and repeatedly and almost proudly admitted he both hates debates and isn’t good at them. (He is a doer, not a talker, a recent ad says.)

But if conservative voters abandon Cain over allegations that he sexually harassed women while he was head of the National Restaurant Association, they have to end up somewhere, so why not with Perry, former darling of the conservative set.

The Texas governor still has a strong resume on job-creation and social issues (though his immigration stance still remains a problem with conservative voters) and if he can make Republicans envision Perry on stage, next to Obama, and not bumbling through a debate, he might begin to have an opening. Or perhaps he can somehow try to prove that debates don’t really matter, a strategy that his team has clearly tried to employ. But that’s a very tall order given that the job of president is akin to being the head of a debate society that is always, always, always in session.

5. Is it Newt’s turn to surge? In Iowa, the buzz is this: After Bachmann’s and Perry’s boom-and-bust cycles, Cain will soon see his numbers drop and conservative voters will give Gingrich, the grand idea man of the GOP, a fresh look. The former House speaker is of course not the world’s most-disciplined politician; his criticism of ideas by GOP favorite Rep. Paul Ryan (R-Wisc.) earlier this year permanently turned off many establishment Republicans. But a strong debate performance by Gingrich, who clearly relishes his turn at the microphone, combined with Cain spending a week on defense denying sexual harassment allegations, could provide another jolt to this bizarre campaign.


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