Romney's chief Iowa rivals press electability DES MOINES, Iowa (AP) - With time running short, Ron Paul, Rick Santorum and other Republican presidential contenders insisted they could beat President Barack Obama as they worked to persuade undecided Iowa Republicans aching to win the White House to choose them over chief rival Mitt Romney. "I'm the candidate that actually was able to win in states, as a conservative, in getting Democrats and independents to vote for us," Santorum, the former Pennsylvania senator who is surging in the race and is a favorite among cultural conservatives, said in an interview on CNN. Mitt Romney has no track history of doing that. Paul, a libertarian-leaning Texas congressman who Romney has said is outside the GOP mainstream, countered the suggestion that he's a fringe candidate. In an interview with ABC from his home state, where he was spending the weekend, Paul insisted: "I'm electable. I've been elected 12 times in Texas, when people get to know me. With Romney in a position of strength in Iowa, both Santorum and Paul went directly at the former Massachusetts governor's chief argument - that he is the most electable Republican in a head-to-head matchup against Obama next fall. They hope they can sway the roughly half of likely caucus-goers who say they are undecided or willing to change their minds two days before the leadoff presidential caucuses. A Des Moines Register poll released Saturday showed Romney and Paul locked in a close race, with Santorum rising swiftly to challenge them. Nearly half of likely Iowa caucus-goers view Romney as the Republican most likely to win the general election. He was far ahead of Santorum and Paul, who was viewed as the least likely to win. Those two are fighting against the notion in GOP circles that their bases of support are narrow and neither would be able to cobble together the diverse voting coalition necessary to beat Obama in November. Paul attracts legions of backers who put states' rights above much else, while Santorum - an anti-abortion crusader - is popular among Christian conservatives who make up the base of the Republican Party. In contrast, Romney has styled himself as a Republican able to attract a broad spectrum of voters. As polls showed him in strong standing in Iowa in the past week, he has redoubled his effort to portray himself as the business-savvy executive with national appeal who is best able to defeat Obama on the campaign's most pressing issue, the economy. Although the race remains fluid, it appeared that Romney's carefully crafted plan to avoid underperforming in Iowa, where he campaigned little until last week, may be working, given a divided GOP electorate torn between several more conservative candidates and Paul's appeal to libertarians. The issue of what type of candidate to choose cuts to the heart of why the Iowa race is so volatile; an NBC/Marist poll last week showed nearly even percentages of Iowa caucus-goers want a candidate who shares their values as want a candidate who can beat Obama. "The first thing you see when you talk to any Iowa Republican is that desire to beat Barack Obama," Iowa GOP Chairman Matt Strawn said. Mindful of that, both Romney and Santorum canvassed the state Sunday to make the electability case - and their schedules illuminated their late-game strategies for rallying their backers to the caucuses. Romney appeared in Atlantic and Council Bluffs as he works to maximize the edge he holds in critical areas, especially those he won in his second-place finish here four years ago, rather than risk underperforming in places where more ardent conservatives are leery of his Mormon faith and shifting positions on social issues. On Monday, he was heading to his eastern Iowa strongholds, Cedar Rapids, Davenport and Dubuque. He is increasingly projecting confidence that he would be the GOP's nominee, promising to return to Iowa, a general-election swing state, in the fall campaign. 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 Thomas Beaumont on Twitter at www.twitter.com/TomBeaumont