Interesting map, and glad to hear about Arizona! I would have to think Illinois' would actually be Notre Dame, with Iowa or Missouri in second? I actually did a very involved Excel spreadsheet (using estimated data, of course, based on several polls I could find) where I broke down Illinois into population segments and estimated what percent of each region (Chicagoland, Northern IL, Central IL, etc.) even had a favorite team for NCAAF and then the estimated fan breakdown ... here's what I came up with statewide:
42.29% Illinois
16.07% Notre Dame
3.94% Iowa
3.75% Missouri
3.69% Northern Illinois
3.44% Wisconsin
2.96% Michigan
2.81% Northwestern
2.72% Indiana
2.04% Michigan State
.94% Kentucky
15.36% Other
Chicagoland was:
28.38% Illinois
22.08% Notre Dame
4.90% Northwestern
4.14% Northern Illinois
3.83% Wisconsin
3.69% Michigan
3.69% Indiana
3.56% Michigan State
3.50% Iowa
22.24% Other
I tried to include factors such as living alumni in the area/state, fan polls I could find and then combining Common Census and NYT Zip Code Map data.