Mitt Romney won the Illinois Republican primary on Tuesday, securing a double-digit victory over his closest competitor, Rick Santorum. Ron Paul and Newt Gingrich trailed far behind, with neither securing more than 10% of the vote. Exit polling shows that Romney continues to draw less support from white born-again/evangelical voters than from non-evangelicals, while Santorum has yet to secure an outright victory among Catholic voters in any state for which data are available.

Voting by Born-Again Status 

White evangelicals made up 42% of Illinois primary voters, and 46% of them voted for Santorum while 39% supported Romney.¹ Among non-evangelicals, Romney was the winner with 54% support, compared with 26% who voted for Santorum.

Voting by Religious Affiliation and Worship Attendance 

Among Illinois Protestants (who accounted for 56% of the GOP primary electorate), 45% voted for Romney while 38% backed Santorum. Romney was the clear winner among Catholics, who made up roughly one-third of Illinois primary voters.  Romney garnered 53% support from Catholics, compared with 30% for Santorum.

Half of Illinois primary voters said they attend religious services on a weekly basis. This group split its votes between Romney (44%) and Santorum (39%). By contrast, Romney was the clear winner among the roughly one-third of Illinois voters who said they attend religious services occasionally; 54% voted for Romney compared with 26% who supported Santorum.

Voting by Importance of Candidates’ Religion 

Santorum was the favorite of Illinois GOP voters who said that it matters a great deal that a candidate shares their religious beliefs, securing half the vote (51%) among this group. There was a more even split among voters who said it matters “somewhat” to them that a candidate shares their religious beliefs, with 46% supporting Romney and 37% backing Santorum. Among voters who attach little or no importance to having a candidate who shares their religious beliefs, Romney was the clear winner, securing 59% support compared with 22% for Santorum.

This analysis is based on results from exit polls conducted as voters left the polls during the Illinois Republican primary election. The polls were conducted by Edison Media Research for the National Election Pool. Full results and additional details from the Illinois exit poll can be accessed at http://www.cnn.com/election/2012/primaries/epolls/il. 

This analysis is based on exit poll data that were available as of 1:00 p.m. on March 21. Exit poll data are sometimes reweighted, so some figures may be different from those available on CNN.com. 

Footnotes:  

1 Voters can describe themselves in exit polls as born-again or evangelical Christians regardless of their religious affiliation, meaning that the born-again/evangelical category likely includes not only Protestants but also some Catholics and even some voters who say they have “no religion.” (return to text) 

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