MESA, Arizona - Maybe it was the fact that the candidates were forced to sit in an odd, uncomfortable configuration. Or, maybe it was that after twenty of these debates, these four candidates are just really tired of the routine. Or, maybe it was the Arizona sun that sapped the candidates of the energy and verve they have shown in previous debates.

Whatever it was, this final - maybe - GOP primary debate was not a particularly strong one for any candidate. It generated a lot of light, but very little heat. And, it did produce one sure loser: Rick Santorum.

Winners:

Mitt Romney: As he did in the Florida debates when he relentless attacked Newt Gingrich, Romney came to Mesa loaded for bear. Just a few minutes into the first question, Romney was already turning his sites on Rick Santorum. And, it worked as he kept Santorum on his heels for the entire evening.

But, in the end, Romney didn't really "win" anything. He didn't make a strong case for himself or his own record. He didn't put to rest concerns about his lack of a bigger, broader vision for November. He didn't make the case for himself as much as he made an effective case against Santorum.

Newt Gingrich: One never knows which Newt is going to show up on debate night. Angry Newt? Pensive Newt? Complacent Newt?

Tonight he was "cheerful" Newt. Instead of pouncing on Romney or Santorum, Gingrich deflected and even backed up his foes.

So, why the Mr. Nice Guy routine? He has no choice. The most recent ABC/Washington Post poll showed just what kind of damage the relentless attacks by Romney and his allies have taken on Gingrich's approval ratings. Just 45 percent of GOP voters said they viewed the former Speaker favorably - 42 percent viewed him unfavorably. These are his lowest marks yet in this campaign. If he goes on the attack, his ratings stay in the basement.

Even so, when Gingrich stays above the fray - especially when his opponents are sniping at each other - it helps him.

President Obama: Every minute the GOP candidates spend debating "Romneycare," earmarks, and contraception is a good minute for the president. Nothing helps a president look, well, presidential, than a debate where the opposing party's candidates spend most of their time sniping at each other.

Phoenix: Okay, so the race in Arizona is not nearly as competitive as it is in Michigan. And, no one but the Romney SuperPAC is spending money on TV ads. But the weather is just so wonderful, it is hard not to cheer for this state keeping its February primary date.

LOSERS

Rick Santorum: Whatever momentum Santorum had came to a screeching halt in tonight's debate. Romney lured Santorum time and again into defending his record in Washington. And, Santorum took the bait - responding to his attacks with process arguments and Washington gobbleygook speak.

Example: Romney attacks Santorum for his record on earmarks and Congress' voracious appetite for spending. Santorum's response: "What happened the - the 12 years I was in the United States Senate, we went from the debt to GDP ratio, which is now over 100 percent. When I came to the Senate it was 68 percent of GDP. When I left the Senate it was 64 percent of GDP."

Um, what?

Instead of turning Romney's attacks into an opportunity to get on the offense and back on message, Santorum spent his time explaining - and explaining - and explaining.

Santorum has spent the last couple of weeks portraying himself as an outsider. He undid all of that work in tonight's debate.

Jan Brewer: With just six days until the primary, and as much as half the GOP vote already cast, the Arizona Governor is still waiting to endorse a candidate. Did tonight's debate help her make a decision?

"I have a lot to digest and absorb," she told the media horde surrounding her in the spin room tonight.

Yet, by tomorrow, the national media, and the candidates will have fled the warmth of Arizona for the cold, hard truth of Michigan. Her chance to get into the spotlight has passed.