12/16/2011 12:43 am ET Updated Dec 16, 2011

GOP Debate: The Second Tier Makes Its Final Pitch

SIOUX CITY, Iowa -- In the final Republican debate before the Iowa caucuses on Jan. 3, the candidates who are mired in second-tier status tried as best they could to make a final impression on the state's voters.

While former Massachusetts Gov. Mitt Romney played it cool and former House Speaker Newt Gingrich (R-Ga.) kept to his campaign script of not attacking other candidates, Rep. Michele Bachmann (R-Minn.), former Sen. Rick Santorum (R-Pa.) and Texas Gov. Rick Perry were grasping for moments in which they could attain first-tier status.

The three candidates are hoping to gain enough traction in Iowa to be able to continue their campaigns after Iowa voters make their decision. And with three weeks to go, the tactic that seemed the most obvious was to take on Gingrich's weak spots, with a subtle dig at his "personal life" by Santorum and criticism of his work with government-sponsored enterprise Freddie Mac by Bachmann.

"We know that he received paychecks from Freddie Mac," Bachmann said. "The speaker had his hand out and he was taking $1.6 million to influence senior Republicans to keep the scam going in Washington, D.C."

Santorum criticized Gingrich after he was asked about his own poll numbers in Iowa, which have remained low despite his heavy campaigning in the state. Santorum said that he has been a strong supporter of conservative values, implying Gingrich has been less consistent.

"The speaker had a conservative revolution against him when he was the speaker of the House," Santorum said. "I have conservatives knocking down my door because I was the effective advocate for the principles that they believed in. That's the contrast."

"We need someone who's strong in their political and personal life to go out and contrast themselves with the president," he added, in a possible allusion to Gingrich's marital history.

If Bachmann, Santorum or Perry were to have a poor showing in the Iowa caucuses, each would likely feel pressure to drop his or her campaign for the nomination. Of the three, though, Perry has the most money at his disposal and could be most likely to press on, particularly if he continues to gain back some of the momentum he has lost.

He had a solid showing in the debate, without the major stumbles that have plagued some of his previous debate performances.

"I'm kind of getting where I like these debates," Perry said. "As a matter of fact, I hope Obama and I debate a lot. And I'll get there early."