GOP Field Set to Take Aim at Gingrich During Tonight’s 9:00 Debate

National Journal Reports: Can Mitt Romney prove to Republicans the surging Newt Gingrich shouldn’t be their presidential nominee? Saturday night will give him a golden opportunity.

The GOP presidential field will gather in Des Moines, Iowa, for its 12th debate, but its first since Gingrich became the undisputed leader in most polls. His rise has come at the expense of Romney, once the clear front-runner, and now the ex-governor of Massachusetts must play catch-up. With just three weeks left before the Jan. 3 Iowa caucuses, he doesn’t have much time left.

It’s why his campaign started in earnest this week criticizing the former speaker of the House, with several of Romney’s top surrogates calling him untrustworthy, selfish and unfit to be commander-in-chief. Most of all, Romney has sought to hit Gingrich on his previous disparagement of House Budget Chairman Paul Ryan’s Medicare-reform plan, arguing it showed he’s not a reliable conservative.

The attacks so far have been carried out by Romney allies, like former New Hampshire Gov. John Sununu. Saturday’s debate will test whether the candidate himself is willing to criticize Gingrich. The position is an unfamiliar one for Romney, who’s largely been able to rise above the criticism from his opponents as he held a firm grip on the race’s front-runner’s mantle. Now, he must battle with Gingrich to chip away at the support he’s earned among conservative and even some moderate Republicans.

For Gingrich, Saturday night will test whether he will continue to avoid criticizing his Republican rivals, as he’s insisted on doing through most of the campaign. The ex-congressman’s refusal to attack his opponents during debates, often opting instead to criticize the media or moderates asking the question, has been a hit with conservative audiences and the primary reason he’s been able to claw his way back into the GOP race.