For the fifth time in the last six weeks and the eighth time in 2011 — neither of those are typos — the Republican presidential field will gather on a debate stage with Las Vegas providing the backdrop to tonight’s tete a tete.

HANOVER, NH - OCTOBER 11: Former Massachusetts Gov. Mitt Romney (R) speaks as Texas Gov. Rick Perry (L) and former CEO of Godfather's Pizza Herman Cain (C) look on during the Republican Presidential debate hosted by Bloomberg and the Washington Post on October 11, 2011 at Dartmouth College in Hanover, New Hampshire. (Photo by Justin Sullivan/Getty Images)

Of the seven people who will debate tonight, businessman Herman Cain and former Massachusetts governor Mitt Romney — the two frontrunning candidates — are likely to get the lion’s share of questions from the moderator (CNN’s Anderson Cooper) and attention from their rivals.

But, Texas Gov. Rick Perry may have the most to prove as he tries to deliver the solid debate performance that has, so far, eluded him.

The debate starts at 8 p.m. and runs for two hours. CNN is carrying it live and the Fix posse — Fix original recipe, FixAaron and FixRachel -- will be liveblogging the proceedings too.

In the meantime, check out our cheat sheet on what to watch for in tonight’s debate.

* Cain as marked man: The hardest thing in politics, as in life, is to find a second, successful act. While Cain, the former CEO of Godfather’s Pizza, is still riding a wave of momentum, hard questions have begun to be asked about his policies — from the now famous “9-9-9” tax reform plan to his dearth of experience (or hard and fast positions) on foreign policy.

In last week’s Washington Post-Bloomberg News debate, the attacks against Cain were scattershot and largely launched by second or third tier candidates. Perry and Romney ignored him.

Does that change tonight? Do his rivals gang up on Cain — perhaps seizing on his admission over the weekend on “Meet the Press” that “9-9-9” would mean higher taxes for some — and force him on defense? And does Perry, who has fallen as quickly as Cain has risen, lead the charge in an attempt to win back conservatives?

* Perry’s last, best chance (again): By dint of the $17 million he raised (and the $15 million he still has in the bank), the Texas governor will keep getting second (and third and fourth) chances to make a good impression with Republican primary voters.

And, while his advisers publicly insist that the debates don’t matter and have done little to affect the race, it’s hard to argue that Perry’s rapid drop in national and early state polling isn’t directly tied to his lackluster debate performances.

If ever there was a debate where Perry should — and we emphasize should — shine, it’s this one. Set in Nevada, it’s the closest thing to a western state debate Perry has participated in and, as such, his experience and successes in Texas may well resonate better with this audience. It’s also the fifth debate he has participated in so he’s had some practice.

Perry is never going to be the debater that Romney is but he has to reach a minimum bar of credibility to show that yes, Virginia, he really is up to a race of this caliber. Might tonight be the night?

* Mormon mention?: Talk of religion has been largely absent from the debates to date and Romney likes it that way. But the confluence of Nevada’s sizeable Mormon population — 7.5 percent — and the recent controversy over Richard Jeffress’ comments (and his ties to Perry) suggest that tonight may be the night where religion makes a more than a passing appearance.

Since the 2008 campaign, Romney has been open and unapologetic about his Mormon faith but he and his campaign would clearly prefer to be talking about jobs and the economy rather than what he believes and why he believes it.

Without Huntsman (a fellow Mormon) on stage, the burden of explaining/defending his faith will fall entirely on Romney — a less than ideal situation for him.

* Can someone (anyone?) land a punch on Mitt?: Romney has participated in all but one of the eight debates so far this year and has never been bloodied — much less knocked to the debate canvas.

That’s a stark contrast to the 2008 campaign when the field — led by Arizona Sen. John McCain — ganged up on Romney and pummeled him as an unprincipled flip flopper.

This time around the candidates haven’t honed in on Romney and his past record nearly as much, and he has become far better at deflecting the strong punches thrown at him.

But with more and more of the establishment lining up behind Romney and with a majority (albeit only 51 percent) of Republicans saying they expect the former Massachusetts governor to be the party’s nominee in a new CNN poll, time is growing short for his opponents to derail him.

Expect Perry and Cain to try. But Romney is vastly improved as a debater since the 2008 election and will offer no easy target.

* The New Hampshire card: Looming over tonight’s debate is the game of political chicken being staged between Nevada Republican party chairwoman Amy Tarkanian and New Hampshire Secretary of State Bill Gardner. Gardner wants Nevada to move its Jan. 14 caucuses back to Jan. 17 — thus allowing New Hampshire to vote on Jan. 10 — but so far Tarkanian isn’t budging.

New Hampshire is trying to force candidates to take sides in the scrap and, to date, it’s working. Huntsman won’t even be at tonight’s debate while Cain, Minnesota Rep. Michele Bachmann, former House Speaker Newt Gingrich and former Pennsylvania senator Rick Santorum have all pledged to boycott the Nevada caucuses if the state doesn’t change its date.

That leaves a big target on Romney’s back. Romney doesn’t want to say anything negative about Nevada since he won the caucuses easily in 2008 and almost certainly will do so again in 2012. But, he also doesn’t want to make New Hampshire voters, who protect their primary like a mama bear protects her cubs, angry.

Wrote the conservative (and influential) New Hampshire Union-Leader editorial board on Monday: “Romney could put New Hampshire voters’ minds at ease about his commitment to the primary and the value of selecting candidates the old-fashioned way. He could join the Nevada boycott. Or not. Either way, New Hampshire is watching.”

Threat delivered. Let’s see if any of Romney’s rivals try to pin him down on New Hampshire’s primary primacy tonight.