The very Democratic counties in southwestern Wisconsin?

[Starbucks Union Thug HokeyPuck]

I'm interested as to why these counties are so Democratic, most of them giving Obama >60% in the 2008 election and giving Clinton and Gore solid margins before that.  They seem to be overwhelmingly white, not very populated, and contain suburbs of Madison (whereas the Milwaukee suburbs are very conservative). 

The most obvious example is Iowa County and to a lesser extent Rock County.  The trend seems to even extend into counties in southeast Minnesota and northeast Iowa.  Very white, not a lot of people.... but pretty Democratic. 

I would have to guess it has something to do with industry along the Mississippi River but I'm not sure.  Anyone have some insight? 

[Guderian]

Probably a lot of anti-war Scandinavians. Also, Democrats do well almost everywhere near the Miss. river - there's a racial factor to this in the South, but there's also the fact that people living so near to a river so big are probably more inclined to support government activism and have more communitarian worldview.