Mitt Romney is headed for a blowout victory in Illinois on Tuesday. He leads with 45% to 30% for Rick Santorum, 12% for Newt Gingrich, and 10% for Ron Paul.
Romney's particularly strong among voters who live in suburban areas (50-29) and with those who live in urban areas (46-23). But he's even running slightly ahead of Santorum, 38-36, with folks who identify as living in rural parts and that strength with a group of voters he hasn't tended to do that well with is why he's looking at such a lopsided margin of victory.
Romney tends to win moderates in most states and Santorum usually win voters describing themselves as 'very conservative.' The swing group in the Republican electorate is those identifying as just 'somewhat conservative.' Romney is winning those folks by a whooping 60-20 margin in Illinois. Romney's also benefiting from a 52-28 advantage with seniors.
Santorum's winning the group he tends to do well with- Tea Partiers, Evangelicals, and those describing themselves as 'very conservative.' But he's not winning them by the kinds of wide margins he would need to take an overall victory- he's up only 8 with Tea Party voters and 10 with Evangelicals, groups he needs to win by more like 25 points with to hope to win in a northern state. Santorum can't blame Gingrich for his troubles in Illinois either. If Newt was out Romney would still have an 11 point advantage on Santorum, 45-34.
Full results here