Illinois is wide open.
Since we vote by congressional district, Romney could have a 60/40 advantage in a Chicago district and win their delegates, and then Santorum could have just a 51-49 advantage in the suburbs or downstate and win their delegates.
Every district is different. Hearing 41-32-etc. isn’t helpful in a state like Illinois. It’s not proportional, in terms of allocating delegates based on percentages.
Delegates (and the alternates too) run to represent their congressional districts.
Incidentally, regarding the claim that Democrats are meddling... oh yes, dems meddle all the time, but they’re more likely to vote for Romney as the moderate they can more easily beat.
The few remaining dems who cross over to vote for Rick are usually doing so because they agree with him on some major issue, so they would be with him in November.