In the past few debates, the "Five Things to Watch" haven't changed that much. We all want to see how Rick Perry performs, whether Mitt Romney continues to deflect attacks, which one of the second-tier candidates shine or lands a blow, and so on--the usual stuff.
In tonight's debate, however, there is One Main Thing to Watch: the performance of Herman Cain.
If Cain continues to do well in these debates -- and avoids flip statements on things like electric border fences -- he's going to have a major impact on this race.
Already, Cain has shifted the dynamic in ways Rick Perry couldn't possibly have imagined when he announced he was running for president. Perry envisioned a two-man race against Romney, but so far he hasn't gotten the head-to-head matchup he wants.
Campaign insiders and strategists say privately that Cain has surprised them all by leaping over Perry in the polls. Cain, not Perry, is now neck-and-neck with Romney.
If anything, the more voters see of Rick Perry, the more they seem to like Herman Cain.
The question for Cain--not only in tonight's debate, but in this campaign--is how he will run as a frontrunner and with a largely grass roots campaign. So far he's rising to the occasion. The man isn't lacking in confidence.
Consider for example how Perry and Cain have handled the issue of religion, which I expect CNN's Anderson Cooper, the debate moderator, to bring up tonight. Perry needs the support of evangelicals -- who, for example, made up 60 percent of Republican voters in 2008 in Iowa -- to beat Romney. That could explain his refusal to more forcefully denounce two evangelical leaders (both Perry supporters) who have questioned Romney's faith and called Mormonism a cult.
But as Perry plays the balancing act on Mormonism--and sends his wife Anita to South Carolina to talk about his Christian faith--Cain delivers straight talk.
In an interview with the Associated Press over the weekend, Cain said he's a "staunch Christian conservative," but he just doesn't wear it "on my forehead."
Cain said Perry was wrong to think he would carry the evangelical vote -- because he has a message for those voters, too. Perry "thought he had carved out that niche," Cain told the AP, "when he didn't own that niche by himself."
I watched Cain work the crowds over the weekend, and I sat down with him Sunday afternoon. Some of the things you hear from the pundits who refuse to take him seriously are true. Perry is crushing him in fund-raising and in the number of campaign staffers he employs. And there's Cain's 9-9-9 flat tax plan, which has its share of skeptics.
But I wouldn't be so quick to overlook what Herman Cain also has: a message of hope and optimism that Republican voters want to hear -- and a willingness to say things most politicians won't.
A recurring theme in Cain's new book is how he refuses to quit when challenged. He bets on himself. He works harder.
And then when he takes heat -- as when he said blacks were "brainwashed" into voting lockstep for the Democratic party, or when entertainer and activist Harry Belafonte called him a "bad apple" -- he doesn't back down.
"Harry Belafonte called me a 'bad apple.' Okay, what's a 'good apple?'" Cain told me. "A good apple is a Democrat, a liberal, who shuts up and does what he or she is told and doesn't make waves. That must be a good apple. If that's a good apple, then by definition I am a bad apple. Because I think for myself. I am a conservative. I am running for president as a Republican and I'm going to win."