At stake this time is whether Mr. Gingrich, despite a past that some conservative Christians say should disqualify him, can benefit from the aversion of many evangelical leaders to Mitt Romney, whose Mormon faith and history of having once supported abortion rights has left many on the religious right wary — or whether the support of evangelicals will be dispersed, undercutting their influence and giving the rest of the field a clearer shot at a strong showing.

Other candidates, like Representatives Michele Bachmann of Minnesota and Ron Paul of Texas; Rick Santorum, the former senator from Pennsylvania; and Gov. Rick Perry of Texas, are also aggressively courting evangelicals. Mr. Perry used Saturday night’s debate to fault Mr. Gingrich for his three marriages, while on Sunday he accused President Obama of waging a “war” on religion.

Mr. Vander Plaats, after yet another meeting last week with his team at their offices in Pleasant Hill, Iowa, lamented that “the candidate that the conservatives most don’t want, they might get because they fragmented their support.”

“That’s the dilemma we’re faced with today,” he said.

But there are signs that Mr. Gingrich is making inroads among evangelicals as among all voters in Iowa. A New York Times/CBS News poll released last week of likely Republican caucusgoers showed that Mr. Gingrich had the support of 33 percent of self-identified evangelicals and born-again Christians, while Mr. Perry had 16 percent and Mr. Paul 15 percent, with Mr. Romney capturing only 10 percent.

Around here, Mr. Romney is portrayed as a big-government progressive, a bit too slick as a politician and far too prone to changing his positions. He has not been helped by limiting the amount of time he has spent campaigning in Iowa, which has struck some voters here as — in the words of Steve Scheffler, a veteran organizer and president of the conservative Iowa Faith and Freedom Coalition — “political bad behavior.”