To be fair, I mostly talk to academic types. I once met a PhD student at UW who had lived in Madison for 7 years and didn't know the difference between the packers and badgers
There's plenty of 'T-shirt' Badger fans for sure.
Now at bars when I used to go watch games I had to repeat 'I-O-WUH STATE' a couple of times to bar tenders because they automatically thought I was asking for Ohio State.