Mitt Romney's win in the Illinois Republican primary rested on broad leads among voters with higher incomes and more formal education, with a boost from those focused on defeating President Barack Obama in November, according to an exit poll conducted for The Associated Press in the state.
KEYS TO THE MIDWEST: As in Ohio and Michigan, where Romney eked out narrow victories over Rick Santorum, the two candidates ran about evenly among those with lower incomes and less formal education. But Romney outperformed his showing in the other two Midwestern states among higher income, higher educated voters. Romney more than doubled his margin over Santorum among college graduates, prevailing by 22 percentage points in Tuesday's primary, and nearly did so among those with incomes above $100,000, carrying those voters by 27 points.
ELECTABILITY PROPELS ROMNEY: Romney won 74 percent voters who said it was most important to choose a candidate who could win in November. Aside from Massachusetts and Virginia, where only Romney and Ron Paul were on the ballot, that is Romney's best performance among this group.
TEA PARTY BACKERS: Romney topped Santorum among tea party backers, 47 percent to 36 percent. The two split the group about evenly in Ohio and Michigan, and Romney has only won them by a significant amount in five other states where exit or entrance polls have been conducted.
A DIFFERENT RELIGIOUS COMPOSITION: About 4 in 10 voters were white, born-again Christians, well below the levels seen in last week's primaries in Alabama and Mississippi, but above the 34 percent of Illinois GOP primary voters who were white evangelicals in the 2008 exit poll. These voters broke for Santorum, who held a 20-point lead among voters who said it was deeply important that a candidate share their religious views.
But Santorum again did not appeal as strongly to his fellow Catholics as he did to evangelicals. Overall, 35 percent of Illinois GOP voters were Catholic, among the highest levels seen across 11 states where GOP voters were asked their religion. Romney, who is a Mormon, won 53 percent among Catholics, compared with 30 percent for Santorum. And while Santorum held a wide lead among evangelical Christians who attend services weekly, among Catholics who do the same, 48 percent favored Romney, 39 percent Santorum.
SANTORUM STRONG AMONG CONSERVATIVES: Among the 3 in 10 voters who called themselves "very conservative," Santorum held a double-digit lead. However Romney won 52 percent to 29 percent among all others.
Among those voters who said it was most important to choose a true conservative, Santorum held a better than 6-1 margin over Romney. About 4 in 10 voters overall in Illinois said Romney's positions on the issues were not conservative enough, but the former Massachusetts governor still carried 25 percent of the vote among this group. Santorum, by contrast, won just 6 percent of the vote among those who considered his positions too conservative.
ECONOMIC VIEWS: Most Illinois voters called the economy their top issue in choosing a candidate, while a quarter called the deficit tops. About half of voters in both groups said they supported Romney. Nearly half of voters said the nation's economic conditions were getting worse and another third said they were staying about the same. Just 22 percent saw the economy as improving.
Economy voters were a bit more likely to say they were seeking a candidate with the right experience, and that was another group Romney dominated. Among those who said a candidate's experience was the most important factor, Romney trounced his opponents, 64 percent to 15 percent for Newt Gingrich, 11 percent for Ron Paul and 8 percent for Santorum.
NOT SEEKING A QUICK END: About a third of those who voted Tuesday said they wanted to see the nomination campaign end quickly. Instead, 66 percent favored a long contest with their favored candidate prevailing in the end. About a third of Romney backers wanted things to end quickly, compared with one-quarter of Santorum backers.
Results from the survey of 1,621 Illinois Republican voters have a margin of sampling error of plus or minus 4 percentage points. The exit poll was conducted for The Associated Press and the television networks by Edison Research at 35 randomly selected polling places around the state.
Earlier on HuffPost: