From Democratic firm Public Policy Polling:
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.
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.
Santorum support tends to be understated in polls; he usually does a few points better than his final poll numbers in the actual primary or caucus. But gaining three to five points tomorrow won’t be enough to pull off a win, if PPP’s analysis of Romney’s support is accurate.