WASHINGTON -- Voters hunting for a candidate who can defeat President Barack Obama and with the proper experience helped vault Mitt Romney to victory Tuesday in Illinois' presidential primary, according to preliminary results of an exit poll of voters. His win was also powered by robust margins from people worried about the economy and federal deficits.
Main challenger Rick Santorum ran strongly among people who want their contender to be a true conservative and to exhibit strong moral character, and with the most religiously driven voters. But Illinois only has modest proportions of such voters, narrowing the former Pennsylvania senator's appeal.
"Romney is a little too liberal for the Republican base. But that's the only way you can win. You've got to get the independents," said Norm Jay, 78, of Wheaton, who backed the former Massachusetts governor.
Underscoring how the Illinois contest occurred on terrain that was not the friendliest for Santorum, a third of those voting on Tuesday called him too conservative. That was the highest proportion of voters expressing that view in any of the half-dozen states so far where that question was asked.
Romney was winning the votes of nearly three-fourths of people seeking a candidate who can defeat Obama. Among 17 states where voters have been polled so far, that proportion has only been surpassed in Romney's home state of Massachusetts and in Virginia, where he and Texas Rep. Ron Paul were the only competitors.
Romney was also getting more than 6 in 10 votes of people seeking the right experience. Combined with those seeking a candidate who can best handle Obama, that gave Romney a forbidding lead among over half of those who showed up to cast ballots, the survey showed.
Romney, who has used his business background to cast himself as the candidate best equipped to create jobs and eliminate federal waste, led Santorum by 20 percentage points among voters riveted on the economy and the federal deficit as top issues. People with those concerns accounted for more than 8 in 10 voters, making Romney's strong edge with this group impossible for Santorum to overcome.
Voters from families earning at least $100,000 a year and college graduates also tilted strongly toward Romney. That proved decisive, since those earning less than that amount and those without degrees split about evenly between him and Santorum.
Santorum, outspoken on the campaign trail about the importance of faith, had a nearly 2-1 lead over Romney among voters saying that sharing religious beliefs with a candidate mattered greatly. Such voters, though, accounted for just shy of 1 in 4 voters, a slightly smaller share than average among states whose voters have been surveyed so far.
Around two-thirds of the votes of those seeking a real conservative and a contender with strong character were backing Santorum. But such voters comprised less than half the overall vote.
"I don't know if he (Romney) is willing to deal with the hard issues or if he would back down from them," said Don Gramer, a Santorum voter who works for the Catholic diocese in Rockford, Ill.
Though Santorum was leading among those considering themselves very conservative, Romney had a narrow lead with all conservatives and a strong advantage among moderates.
Santorum, a devout Catholic, was trailing Romney by about 20 percentage points with Catholic voters, a problem he has encountered consistently this year. While the two men ran about even among Catholics who attend church weekly, Romney had more than a 2-1 lead with Catholics who go to services less frequently than that.
Analysts have said that for Catholics, religious identity is a weaker factor in determining political views than it is for some other faiths. Further showing how the makeup of Illinois voters worked against Santorum, he led Romney by around 10 percentage points among white born-again and Evangelical voters, a group with whom he has generally prospered since the Super Tuesday primaries earlier this month.
But they only accounted for around 4 in 10 voters in Illinois, a bit lower than average in voting so far. Among the nearly 6 in 10 Illinois voters not in that group, Romney had a commanding 2-1 advantage.
Asked which candidate they would back if only Romney and Santorum were in the race, the difference in support between the two men narrowed a bit. That suggests that it might be to Santorum's advantage if former House Speaker Newt Gingrich and Texas Rep. Ron Paul dropped out of the race, which neither has suggested they are about to do.
Even as the third month of the GOP nominating battle nears a close with no end imminent, only 3 in 10 Illinois voters said they want the race to end as fast as possible, even if their own candidate loses. Some Republicans have expressed worries that the length of the campaign has hurt the party's chances of defeating Obama because of the intense, repeated criticism the GOP contenders have fired at each other.
The survey of 1,621 Illinois voters was conducted for The Associated Press and the television networks by Edison Research. Interviews were conducted as voters left their polling places Tuesday at 35 randomly selected sites. The survey has a margin of sampling error of plus or minus 4 percentage points.