I did not adjust the percentage of registered voters that voted in 2008 for the number of 2008 registered voters, but rather simply assumed the 2011 GAB count of registered voters in each county was reasonably close to the number of registered voters in 2008 and 2010. The chart below demonstrates that without controlling the analysis for strength of candidate or platforms, a higher voter turn-out in Wisconsin does substantially favor the democratic candidate. Counties that vote Republican typically have greater voter turn-out in low voter turn-out elections than blue counties. In 2010, a low turn-out year, the four counties with the highest percentage turn-out were all red counties: Waukesha (71%), Sheboygan (68%), Washington (66%) and Ozaukee (66%). By comparison, Dane County fell short of reaching 66% of the registered voters participating in the 2010 election, Milwaukee staggered in with 62%, and democratic stronghold counties like Eau Claire, Rock, and La Crosse, fell well short of 60% participation by registered voters.
2008 was a high turn-out year, and every single one of the nineteen counties trended more towards the democratic candidate (Obama) than in 2010, often by a huge amount. So, if in fact the turn-out today ends up being like 2008 as some are now predicting, the polling that has occurred leading up to today may have come up a cropper in predicting the outcome of the race. As you study the difference between the vote totals in the two elections, remember that Governor Walker won by just under 125,000 votes in 2010.