Actually, it’s the suburban parts of this state that are more solidly Republican. A lot of rural areas are more liberal-leaning, especially in Northern Minnesota (and not just on the Range). This is a phenomena that seems to be unique to Minnesota, Wisconsin, and eastern Iowa.
I believe the basis for this is that farmers in these 3 states, particularly Minnesota, are Democrats (DFL stands for Democrat-Farmer-Labor). Probably dating back to FDR and farm subsidies.