At one point, he promised to veto the DREAM Act, which would provide conditional permanent residency for some illegal immigrants. While Romney has faced criticism for changing stance on some social issues, he has held to a strict position on illegal immigration during his 2012 campaign.
Romney planned to campaign Monday in cities he won four years ago — Cedar Rapids, Davenport and Dubuque. He wants to maximize the edge he holds in critical areas rather than risk underperforming in places where more ardent conservatives are leery of his Mormon faith and shifting positions on social issues.
Santorum, meanwhile, looked to capitalize on his recent surge in polls by focusing on southern portions of rural Iowa, where the former Pennsylvania senator has made a point of visiting more often than his rivals. And he rolled out a new TV ad casting him as "a trusted conservative who gives us the best chance to take back America."
He claimed momentum Saturday — and acknowledged his opponents had more money — as he traveled with his daughter Liz, who quit college to campaign for her father.
"We believe that ultimately, money doesn't matter in Iowa," Santorum said at a packed stop in Indianola. "You can't buy Iowa. You've got to go out and work for Iowa votes."
Perry's advisers see Santorum within reach and have begun attacking the former senator for having supported spending on home-state pet projects, an unpopular position in these tough economic times.
"I think the world of Rick Santorum. He's got a great family. But we've got some real difference when it comes to fiscal issues," Perry told supporters in Boone. "Those differences couldn't be clearer when it comes to important issues in this election like spending."
Santorum, in turn, charged Perry with hypocrisy: "He had a paid lobbyist in Washington looking for earmarks."
Perry has seen his fortunes improve some in recent days in part because he and his allies have advertised the most aggressively. Of the more than $3 million in television ads he has spent, the final round included spots promoting him as a Washington outsider, and Santorum, Bachmann, Gingrich and Paul as insiders.
Perry announced he would travel directly from Iowa to Greenville, S.C., the day after the caucuses, bypassing next-up New Hampshire. Still, he said he planned to participate in two debates in New Hampshire next weekend.
Gingrich, for his part, was spending the weekend pleading anew with Iowans to side with him despite what they have learned about him through millions of dollars in attack advertising by Paul and a political action committee bankrolled by Romney supporters.
"Iowa could actually dramatically change people's understanding of what works in politics if you repudiate that kind of negativity," Gingrich told 150 people at a Council Bluffs restaurant Saturday.
Illustrating the split among social conservatives, Des Moines-area talk radio conservatives Simon Conway and Steve Deace made competing endorsements Friday — Conway for Perry, Deace for Gingrich.
Bachmann, who had fallen since last summer to single digits in Iowa polls, spent the day at her Des Moines-area state campaign headquarters rallying supporters and volunteers. Ten protesters connected to the nationwide Occupy movement were arrested outside the office in a suburban strip mall. Bachmann did not come outside of the building.
Associated Press writers Holly Ramer in Campton, N.H., Steve People in Hampton, N.H., and Shannon McCaffrey in Council Bluffs, Iowa, and Brian Bakst in Urbandale, Iowa, contributed to this report.
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