After returning from Minneapolis for the first two games, I was thinking why so many Twins fans assumed, just because I was wearing a Cubs jersey and hat, that I was from Chicago. I politely told them I was from Iowa, home of the Cubs AAA team.
As you can see on the link to this fanshot, Cubs radio is broadcast all over Iowa, plus into Kansas, Nebraska, South Dakota and even Minnesota (a station I can get throughout most of the state). Was it any wonder that Saturdays recent game there were almost 40% Cubs fans at an away game? And, most were upper midwest area fans that found an easy way to see their favorite team play, despite the record.
The Cubs footprint is very large and the popularity of WGN radio is enormous. Hard for Twins fans to understand I'm sure.