Can’t link easily from my phone, but search for “Naperville legislature wants Big Ten to add another Illinois school” in the Naperville Sun.
It is just a proposal for a feasibility study, and some of the justifications are just silly, but they are definitely on the right track.
I would go much further. Get OOS enrollment up to 50% at UIUC and start filling all departments with tip top students. Create a real honors program and use merit money aggressively to make it all happen. Illinois has the population of top tier students to make it possible. The new flagship can support the overflow of good (but not tip top) students who are crowded out.
It would take many years to pull off but in the end you would have (well, could have) a much higher percentage of tip top students staying in the state (and not just for school) and a much more financially stable University system (due to both OOS tuition and the increase in prestige which will feed directly into endowment*). You would not have the yield problem you have now because UIUC would be the ultimate target school for Illinois residents (as U of Michigan is for it’s residents).
Think big or go home. Lots of small thinkers at UIUC. Just look at the cancelation of EA and the disaster it hath wrought with the 35 day application extension.