Chicago, like many cities around the Great Lakes, has the Northern Cities Vowel Shift. Its spread is something like this, although I've usually seen a tendril extend to St. Louis:
Although Minnesota is starting to be affected by some of the changes that occurred in the Northern Cities Vowel Shift, it also has some differences of its own from surrounding locations, as well as some changes that are oozing in from the west. I'd put the dividing line between the dialect that characterizes Minneapolis and the dialect that characterizes Chicago at somewhere around Eau Claire. See also Benson, Fox, and Balkman (2011).
would you say Jim Sensenbrenner has the typical Northern Cities Vowel Shift dialect?
