There is a deep isolationist streak in the upper midwest, based more on religion than ideology. They may sometimes align with the left but they are definitely separate from them. Like McCain said, Hagel is just wrong on the war.
With that in mind, Hagel is probably one of the people that I would most like to sit down with, with a bottle of bourbon, and debate America's strategic interests.
If I'm not mistaken this was due to a large influx of settlers from Germany and Austria, who generally were opposed to the militarism in those countries at that time. On top of that the first major war America was in after they became citizens was WWI, which led to widespread anti-German feelings, which they naturally did not much care for.