It looks like Mitt Romney is on his way to a victory in tonight’s Illinois primary, with something close to 50% of the vote (CNN results available here). All 4 remaining GOP contenders were on the ballot, and Ron Paul is hovering around 9%, so even if 100% of Rick Santorum’s plus Newt Gingrich’s votes could have been combined behind one candidate or the other, it still wouldn’t have been enough to beat Romney tonight.
NPR has a nice layout of the remaining primary schedule available here. If Romney follows up by doing as well as a close second in Louisiana on March 24, and then wins decisive victories in Maryland, Wisconsin and the District of Columbia on April 3, then it looks as if the race will be mostly decided by the time Rhode Island votes (along with Connecticut, Delaware, New York and Pennsylvania) on April 24.