On Sunday, Romney poked at Santorum directly for the first time since his opponent's rise — though carefully — saying the ex-senator "has spent his career in the government in Washington."
"Nothing wrong with that, but it's a very different background than I have," Romney said in Atlantic in response to a reporter's question, calling Santorum a good guy who has worked hard and probably will do well Tuesday. He also noted that Santorum endorsed him in 2008. It was a delicate attempt to stoke doubts about Santorum without angering — and alienating — his supporters.
Santorum, for his part, was campaigning deep into GOP-rich rural northwest Iowa, with stops in conservative counties won by Mike Huckabee during the former Arkansas governor's victorious campaign here four years ago.
Crowds swelled for a candidate who only recently has moved from afterthought to contender.
"Don't put forward somebody who isn't good enough to do what needs to be done for this country," he implored at a coffee house in Sioux City. He told the crowd that he had more than 1,100 precinct captains to convince undecided voters Tuesday but needs more.
As he met voters, his final ad for Iowa TV called him "a full spectrum conservative" who is most likely to beat Obama and the "trusted conservative who gives us the best chance to take back America."
Their rivals had less aggressive schedules.
Paul, who has slipped somewhat in the wake of attacks on his foreign policy positions, remained out of the state for a second straight day. He was in Texas to celebrate the New Year with his family. But he did a few national TV interviews from Texas, arguing in them that the majority of Americans are with him when it comes to a non-interventionist foreign policy.
"I would say that I'm pretty mainstream," he told CNN and hit his rivals, saying: "People who are attacking me now are the ones who can't defend their records, and they've been all over the place."
Along with Romney, Texas Gov. Rick Perry, former House Speaker Newt Gingrich and Minnesota Rep. Michele Bachmann — all of whom are trailing in polls and fighting for the support of Christian evangelicals — spent the morning in church.
Gingrich went after Romney with abandon, saying he felt like he'd been "Romney-boated" and adding that the multimillionaire would "buy the election if he could."
The nautical attack was a reference to a 2004 TV ad campaign by a group called the "Swiftboat Veterans for Truth" that bloodied Democratic presidential candidate John Kerry. This year, Gingrich has faced an onslaught of negative TV advertisements by a group aligned with Romney.
In all, at least $12.5 million in advertising — much of it negative — has flooded the Iowa airwaves in the run-up to the caucuses as candidates and outside groups aligned with them, called super PACs, worked to influence the outcome of what has been a remarkably fluid and unpredictable campaign.
Working to make up ground quickly, Bachmann and Perry tried to make the electability argument while assailing Santorum, who suddenly has found himself the target of sharp attacks on his conservative credentials from rivals vying for the same bloc of voters.
Bachmann told ABC, "I have the best ability to take it to Barack Obama in the debate and hold him accountable." On Fox, she lambasted Santorum, noting that he was soundly defeated when he ran for re-election in 2006, losing by a 59-41 margin to Democrat Bob Casey.
"I won four races in the last four years, in the toughest years for Republicans — in a liberal state like Minnesota, I won," Bachmann said.
Perry, who never lost an election in Texas but has struggled in his first nationwide race, told "Fox News Sunday" of his opponents, "They may do OK in Iowa, but when it comes to running a national campaign, they're going to falter."
Perry also renewed his attack on Santorum, saying: "He's got a spending problem. He's got an earmark problem. He voted eight times to raise the debt ceiling in the United States Senate."
Associated Press writers Philip Elliott in West Des Moines, Shannon McCaffrey in Des Moines, Brian Bakst in Oskaloosa and Mike Glover in Sioux City contributed to this report.
Follow Beth Fouhy on Twitter at www.twitter.com/bfouhy
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