As usual the results were probably determined by money. Based on the numbers collected by Wisconsin Democracy Campaign, it looks like total spending on Gablemen's behalf was about 50% higher than that for Butler, roughly $1.95 million to $1.25 million, with almost 90% of the spending coming from outside groups running so-called "issue" ads in order to avoid regulations and disclosure requirements.
Below is a map showing the county by county results with an overlay showing Wisconsin media markets. As best I can tell every market was saturated with TV ads except (as usual) area #4, the Minneapolis/St. Paul market. While I was expecting to see Butler perform better in this part of the state due to the absence of attack ads against him, Gableman is from Burnett County, and this gave him an obvious boost in Burnett and probably the surrounding counties.
If I have time I'm going to do another version of the map normalized to the results of the '04 presidential election. This would remove most of the ideological variation between the counties and therefore highlight other effects, which might be rather interesting...
The media markets are:
1. Duluth/Superior
2. Wausau/Rhinelander
3. Green Bay/Appleton
4. Minneapolis/St. Paul
5. La Crosse/Eau Claire
6. Madison
7. Milwaukee
