Ex-yooper here (and soon to be yooper again - we’re moving back). Concerning racism and such topics, I can attest to the fact that the UP is almost all white. The largest minority is probably Native American.
However, I can honestly say that my upbringing was very much colorblind. I never saw anything close to the racism I see in Colorado (where I currently live) in the UP. In my high school, there were a few black kids, a few Jewish kids, and a handful of other minorities (Hawaiian, Asian, etc) and nobody really paid much attention to it. They were all just kids, like the rest of us.
I understand things are different downstate, but I gotta stand up for the UP on this issue. Marquette (my hometown, and the largest town in the UP) is a college town, and is quite hip and diverse. Not a month ago the local theater in Negaunee (town of less than 5000 people 10 miles from Marquette) put on the “Rocky Horror Picture Show” with a very much “out” local gay man playing the Dr., and it went over GREAT. People LOVED it. When I was home last summer, we saw Eddie C. Campbell (blues legend, for those of you not familiar) play at the local club for about a $5 cover charge.
Not all small towns are cultural backwaters consisting of rednecks and intolerance. (Well, OK, maybe all the small towns downstate are (!) hehehe) If you can get past the 300 inches of snow every year, the UP is a great place to visit. After spending 10 years in what’s considered one of the most liberal, hip places in the country (Boulder, CO) I can honestly say that I would prefer living back in Marquette. It’s just better up there.

