Iowa GOP voters see Romney as best Obama opponent WASHINGTON (AP) - Former Massachusetts Gov. Mitt Romney won strong support Tuesday from Republicans seeking a candidate who can topple President Barack Obama in November's elections and from those most concerned about the weak economy, according to an entrance poll of GOP voters attending Iowa's presidential caucuses. Rick Santorum, the former Pennsylvania senator, countered with solid backing from tea party supporters, religious voters and those who ranked abortion as their paramount campaign issue. Each candidate's reservoir of support helped explain a night in which Romney and Santorum were running neck and neck - and ahead of their four other competitors - in the year's first votes as Republicans started selecting their presidential nominee. Running third was Texas Rep. Ron Paul, who scored highly with young voters, independents and people concerned about huge federal budget deficits. Given a choice of four qualities they wanted in their party's nominee, about 3 in 10 said they wanted someone who could defeat Obama this fall. Forty-eight percent of that group said they were backing Romney, more than twice as many as cited any other candidate. I like Santorum's character and values. But I like Romney's experience and record," said Jeff Young, a salesman from Waterloo, Iowa, who said he was split between the two before Tuesday's caucus. He's best-positioned in the most ways to compete with the other party. Santorum, whose candidacy surged in recent days while emphasizing family and faith, was leading among those seeking a candidate with strong moral character, with 40 percent picking him. Santorum and Paul, a libertarian, were running about evenly among those who said they wanted a true conservative as their standard bearer. Nearly 3 in 10 supporters of the conservative tea party movement were supporting Santorum, and about the same proportion of born-again or evangelical voters were also backing him. That gave Santorum a clear lead among both groups, important because each account for about 6 in 10 Iowa GOP caucus goers. Santorum's recent burst of popularity was spotlighted by the entrance poll, which showed he was backed by a third of all voters who said they made their decisions in recent days - more than any other contender. Only about 1 in 7 voters said abortion was the issue that mattered most when they picked a candidate, but an overwhelming 58 percent of them were backing Santorum. Asked the campaign's top issue, about 4 in 10 named the economy. Romney led among that group with support from about a third of them, underscoring the appeal of his background running an investment company before entering politics and his emphasis during the campaign on his business experience. Romney entered the caucuses widely viewed as the favorite to ultimately win his party's nomination, and the opinions expressed by voters in Tuesday's entrance poll underscored his strengths and weaknesses in the GOP contests ahead. Besides his perceived strength as an Obama opponent and among those worried about the economy, Romney was running ahead of his rivals among the 43 percent of Iowa caucus voters who were not born again or evangelical Christians. He was also doing well among those age 65 and up, people earning $100,000 annually or more and the 54 percent who said a business background was more important than government experience to be an effective president. But only 58 percent of Romney's backers voiced strong support for him, a slightly weaker show of enthusiasm than his other chief rivals. He was also running poorly among those considering themselves very conservative, the most ardent tea party backers and born-again and evangelical voters - a crucial portion of GOP voters in South Carolina and some other states in upcoming nominating contests. Paul had the backing of 48 percent of voters under age 30 and nearly as many independents, giving him large leads in both categories. That could be good news for Paul in New Hampshire, where independents represented almost 4 in 10 voters in that state's 2008 GOP presidential primary. Nearly a quarter of Iowa's GOP voters Tuesday were independents, up from 2008, so their proportion in New Hampshire might grow this year as well. About a third of GOP caucus goers said they were most concerned about budget deficits, and 3 in 10 of them picked Paul, more than any of his rivals. Romney, Santorum, Paul and Texas Gov. Rick Perry were running roughly evenly among one-fourth of voters who said campaign advertising played an important role in choosing a candidate - a testament to the millions in TV advertising that blanketed Iowa in the weeks leading up to Tuesday's caucuses. The survey was conducted for AP and the television networks by Edison Research as voters arrived at 40 randomly selected caucus sites in Iowa. The survey involved interviews with 1,787 caucus-goers and had a margin of sampling error of plus or minus 4 percentage points. AP Deputy Polling Director Jennifer Agiesta contributed to this report.