was drawing strong support Tuesday from the most conservative voters in Ohio's Republican presidential primary, according to early results of an exit poll of voters. Yet despite targeting the state's blue-collar voters, they were giving him only a slender lead over rival Mitt Romney, the survey was showing.
Ohio was the most closely watched among the 10 states holding Super Tuesday presidential contests. With many viewing the state as one of Santorum's best chances of slowing Romney's march toward the GOP nomination, the two men were drawing strength from different ideological wings of the party, with Romney faring better with more moderate, less religiously driven voters.
Santorum had a near 20 percentage point lead among Ohio Republicans considering themselves very conservative, and was doing especially well with people who are conservative on social issues like gay marriage and abortion. The former Pennsylvania senator was also doing strongly with born-again and evangelical voters, and had more than a 2-1 advantage over Romney with people saying it was very important that they share religious beliefs with their chosen candidate.
But while he spent much of his campaign seeking to cement bonds with working-class voters by citing his upbringing in Pennsylvania coal country and stressing U.S. manufacturing, he had only a tiny lead over Romney among people without college degrees -- a common measurement for the blue-collar vote.
Romney, the one-time Massachusetts governor, was leading among all but the most ardently conservative voters in Ohio. He was also capturing a majority of those saying they want a candidate who can defeat President Barack Obama this fall, and was leading among voters saying their most important issue is the economy.
In two Southern states where Santorum fought for strong performances, Oklahoma and Tennessee, he was buoyed by voters who said their choices were influenced by religion, exit polls showed. More than two-thirds of voters in both states said a candidate's religious beliefs were important to them.
Santorum's Oklahoma win was fed by a more than 15 percentage point advantage among those religiously oriented voters over both Romney and Newt Gingrich, the former House speaker who was struggling to keep his candidacy afloat. In Tennessee, Santorum's lead over those two men among people looking for a religious match with their candidate was nearly 2-1.
Another Santorum source of strength in Tennessee and Oklahoma were blue-collar voters, who were giving him modest but clear leads over his competitors in both states.
One of Romney's chief selling points is his assertion that his business background gives him expertise on handling the economy, but Tennessee and Oklahoma voters were not giving him an edge on that issue. Romney and Santorum were running about even among Tennessee voters who consider the economy the top issue in the election, while Oklahoma voters focused on the economy gave Romney only a small advantage over Santorum and Gingrich.
The campaign's persistent criticism of Romney's wealth and background as a private equity executive may be hurting him, the exit surveys showed.
Asked in Ohio and Tennessee which candidate best understands the problems confronted by average Americans, Romney scored poorly. Around a third in each state picked Santorum while only about a fifth named Romney.
In Massachusetts, Romney performed strongly among all types of voters.
But that state's GOP voters expressed displeasure with the health care coverage program enacted while Romney was governor, with half saying the measure had gone too far. Romney has been criticized for that plan by his GOP rivals and has pledged, if elected, to repeal Obama's national health care overhaul, which resembles Romney's Massachusetts measure.
In Georgia, an exit poll of GOP voters there shows the victory there by Gingrich, who represented the state in Congress for two decades, was propelled by people saying the former speaker's ties to the state were important.
Gingrich was winning around three-fourths of the votes of Georgia Republicans saying his relationship to the state affected their vote, according to early results from the survey.
Around 6 in 10 said that mattered little to them, and those voters were divided roughly evenly among Gingrich, Romney and Santorum.
In Vermont, Romney did strongly among rank-and-file Republicans. Texas Rep. Ron Paul ran solidly among the 4 in 10 independent voters.
In Virginia, where only Romney and Paul were on the ballot, Romney performed strongly across most categories of voters.
Exit polls were conducted in seven of the 10 states voting Tuesday, sampling groups of GOP voters ranging from the most moderate in Vermont and Massachusetts to the most conservative and religious in Oklahoma and Tennessee.
On two subjects, voters in each of the states voting Tuesday had the same view.
Given a choice of four issues, Republicans in every state named the economy as the one that most concerns them. Given four qualities to look for in a candidate, the one cited most often was an ability to defeat Obama in November's general election.
The Ohio survey was conducted for The Associated Press and the television networks by Edison Research as voters left 40 selected polling places in the state. The Ohio poll involved interviews with 2,702 voters and has a margin of sampling error of plus or minus 4 percentage points.
Edison Research also conducted interviews at randomly chosen polling places in Georgia, Massachusetts, Oklahoma, Tennessee, Vermont and Virginia.