Mitt Romney sought to convert his tentative standing atop the polls into a first-place finish in the caucuses here, telling Iowans on Sunday that he had the “capability to go the full distance” against President Obama, as his rivals beseeched voters not to settle on a candidate lacking full commitment to their conservative values.
Just as confidence had been rising among Mr. Romney and his aides that they could pull off a win here on Tuesday night, they were faced with a fresh challenge from Rick Santorum, who emerged as the latest in a rotating cast of surging alternatives, ebullient about his rising standing in the polls and support from excited crowds on Sunday in Sioux City and Rock Rapids.
“Don’t put forward somebody who isn’t good enough to do what’s necessary to change this country,” Mr. Santorum, the former Pennsylvania senator, declared at a town hall-style meeting in Sioux City, feeding off his new status as a real contender here. “Put forward someone that you know has the vision, the trust, the authenticity, the background, the record, to make that happen.”
First Read: For Santorum, enthusiasm, devotion among faithful
Still decidedly in the mix was Ron Paul, the libertarian-leaning congressman from Texas, whose dedicated followers could still propel him into the lead Tuesday night and in the nominating contests that will unfold in the coming months.
Even though the Republican race remained fluid, the Democratic Party stepped up its involvement in the opposing contest, and several aides to the president’s re-election team arrived here to open a war room at a downtown hotel. The prime target was Mr. Romney. They introduced an Indiana worker who was laid off in the early 1990s when his company was restructured under the direction of Mr. Romney’s investment firm.Iowa’s caucuses do not have an especially good record of predicting Republican nominees. But the result here could be an indicator of whether Mr. Romney, a former governor of Massachusetts, is succeeding in rallying conservatives behind him or whether he faces a months of struggle to win delegates and resolve the rifts within the party. After months of campaigning, a long series of debates and the rise and fall of one challenger after another, no one has yet shown that they can knock off Mr. Romney — but Mr. Romney, despite running a largely mistake-free campaign, has yet to prove that he can break through the ceiling of support of about 25 percent in national polls that has defined his candidacy in a fractured field.
First Read: Romney enjoys slight lead over Paul in latest Iowa poll
Mr. Romney’s campaign aides were watching Mr. Santorum’s new strength carefully. They said that while they were satisfied that Mr. Santorum’s rise was further fracturing the anti-Romney vote between him, Mr. Paul, the former House speaker Newt Gingrich and Gov. Rick Perry of Texas, they could take nothing for granted when only half of likely Iowa caucusgoers say they have committed to a candidate.
And, on a day when all but the most politically involved Iowans were at home celebrating the new year and watching football, Mr. Romney’s campaign workers were calling the homes of potentially supportive caucusgoers they have been recruiting for months, wishing a happy new year to their families along with a gentle reminder to attend the caucuses.
Mr. Romney’s campaign had been optimistic enough about a possible victory here that it decided over the weekend to keep him in Iowa through Tuesday night to be in place for nationally televised interviews from Des Moines on Wednesday morning — a sign that they expected him to be talking about good news here.
But a senior aide, speaking on the condition of anonymity, played down the importance of a first-place showing, saying “our strategy was never based on a win in Iowa” and that the campaign would be “happily surprised” if he were to secure one.
Preparing for a potentially longer fight, Mr. Romney’s strategists in Boston were increasingly turning their focus on New Hampshire, South Carolina and, the biggest January primary state, Florida, where voters are receiving absentee ballots this week. The campaign has been aggressively working to get out the early vote there and his advertising team has begun to inquire about advertising rates across the state.
Senator Charles Grassley, Republican of Iowa, said that the competing messages in the campaign had left economic and social conservative activists “terribly split here.” Most campaigns were in agreement that a win by Mr. Romney would put him in an enviable position to capture his party’s nomination, as he has predicted he would this week.
None of the campaigns are prepared to count out a strong showing from Mr. Paul, who remains a wild card with top-tier — if eroding — poll numbers and a large war chest.
Less certain is the long-term strength of Mr. Santorum, who has struggled to raise money much of this year and ran his first television commercial only at the very end of the campaign here. But nothing fills a bank account like the word “surge” in headlines, and Mr. Santorum’s communications director, Hogan Gidley, said Sunday that his daily donations have increased by 300 percent in the last few days. He said the campaign has bought advertising time in New Hampshire and is “working to put up an ad buy in South Carolina, as well.”
First Read: Romney draws contrast with surging Santorum
Mr. Gidley, who had previously worked for the political action committee of the winner of the Republican Iowa caucuses four years ago, Mike Huckabee, said some of Mr. Huckabee’s supporters in the state were now getting behind Mr. Santorum. Many of those supporters were evangelical Christians. And several potential caucusgoers said in interviews at churches that they had warmed to Mr. Santorum’s candidacy recently and saw him as a viable contender.
Speaking at the Cornerstone Family Church, Michael Stofer, 21, said his vote would largely turn on opposition to abortion and gay marriage and as he saw it, Mr. Santorum’s “views line up very well with the Biblical understanding of those issues.”
But other Republicans said that even though they liked Mr. Santorum best and had problems with Mr. Romney’s past positions on abortion, immigration and gun rights, they were supporting Mr. Romney because they viewed him as a stronger challenger to Mr. Obama.
At the Family Table Restaurant in Atlantic, where Mr. Romney spoke with voters on Sunday, Betty Placzek, 79, said she preferred Mr. Santorum but would caucus for Mr. Romney. “I think Romney can win,” she said. “I like Santorum but he has zilch chance.”
The opposing views went to the central question hanging over the campaign as it enters this crucial first phase of caucusing and voting.
A series of polls, concluding with a Des Moines Register poll released Saturday night, has shown Mr. Romney and Mr. Paul bunched at the top of the pack. The newspaper poll had Mr. Romney at 24 percent and Mr. Paul at 22 percent. It was conducted Tuesday through Friday and has a margin of sampling error of 4 percentage points. But they have also suggested that Mr. Paul’s support has been fading as rivals raise questions about his non-interventionist foreign policy views, and that Mr. Santorum’s support has been building in the final days.
At the Family Table Restaurant in Atlantic, Mr. Romney took a gentle swipe at Mr. Santorum when asked about him by reporters. He began with a smile, saying, “Senator Santorum was kind enough to endorse me last time around, I appreciate that.”
A few moments later, Mr. Romney added: “Like Speaker Gingrich, Senator Santorum has spent his career in government, in Washington — nothing wrong with that, but it’s a very different background than I have.”
Still, Mr. Romney mostly ignored his Republican rivals and trained his gaze on Mr. Obama.
“This is a failed presidency,” Mr. Romney said. “These have been a tough three years and he is trying to find someone to blame.”
Continuing its strategy of going after Mr. Romney even before the Republican primary voting begins, the Obama campaign held a news conference in Des Moines to highlight Mr. Romney’s record as chief executive of the private equity firm Bain Capital.Mr. Gingrich, who has dropped precipitously in polls while under attack by a ”super PAC” supporting Mr. Romney, told reporters traveling with him that “Romney called himself a moderate as governor.”
Complaining of being “Romney-boated” — a reference to the group that attacked Senator John Kerry of Massachusetts in 2004, Swift Boat Veterans for Truth — Mr. Gingrich said that by damaging him, the ads had only “guaranteed that some other conservative emerged,” an apparent reference to Mr. Santorum.
Jill Abramson contributed reporting from Council Bluffs, Iowa, and Michael Barbaro and Sarah Wheaton from Des Moines.
The article, "In Iowa, Romney tests his ability to take the lead," first appeared in .