The votes are now in for Wisconsin's "non-partisan" Supreme Court race, which featured incumbent David Prosser, a former Republican state legislator, and Assistant Attorney General JoAnne Kloppenburg, who worked for both Democratic and Republican Attorneys general. Prosser was clearly the favored candidate by conservative and Republican groups, and, despite her bipartisan employment history, Kloppenberg received strong support from Democratic and liberal groups, thus setting this up as another in a long line of potentially very partisan non-partisan Supreme Court elections in Wisconsin.
One name that was not on the official ballot, but which played a prominent role during the campaign, was that of Republican Governor Scott Walker. The election took place against the backdrop of pitched political battles and unprecedented protests surrounding Governor Walker's proposed and enacted changes to the state budget, including a measure that would virtually eliminate collective bargaining rights for public employees. Kloppenberg and allied groups highlighted Prosser's political connections, past and present, with the governor in an effort to tie Prosser to Walker and make the race a referendum on the Walker administration. Given this context, it seemes reasonable to expect that voters would be able to pick up on the abundance of cues and sniff out the candidates' partisan connections. In other words, this "non-partisan" election seemed ripe for party-line voting.
In the absence of individual-level data on party and vote choice, I turn to an analysis of aggregate voting trends to examine the role of partisan forces in this election. In the figure below I show the county-level relationship between percent voting for Obama in 2008 (this is my admittedly rough county-level indicator of Democratic tendencies) and percent voting for Prosser in last Tuesday's election.
Lo and behold, that was a pretty partisan non-partisan election. Quite simply, there is nothing "non-partisan" about the county-level voting patterns shown above. Based on this relationship, we might conclude that the combination of the contemporary Wisconsin political scene, along with obvious attempts to to make the election about Governor Walker, served to prime party identification as voters went to the polls. Of course, absent individual-level data, we don't know how Democrats and Republicans voted, but the aggregate pattern certainly suggests they chose different candidates.
An alternative hypothesis, however, is that despite the special conditions surrounding this election, there is nothing particularly special about the level of party voting in 2011. In fact, Wisconsin Supreme Court campaigns usually feature an abundance of partisan and ideological cues that should serve to facilitate party voting. So it's possible that the pattern shown above is not much different from previous non-partisan Supreme Court contests.
To a large extent, this point is supported with data from the previous three WI Supreme Court races (below). Although the relationships vary a bit from year to year, and each of these races has it's own unique story to tell, there is generally a strong and negative county-level relationship between support for Obama and support for the conservative/Republican court candidate.
Although there is a strong partisan pattern in each of these election, the 2011 election does seem to represent a high-water mark for partisan voting. Having said that, it should be noted the the 2008 contest between Michael Gabelman and Louis Butler showed nearly as strong a partisan pattern. I guess the bottom line here is that while the 2011 race stands out as somewhat more partisan than previous contests, there's nothing particularly non-partisan about Wisconsin's Supreme Court elections.