Washington (CNN) - An election Tuesday in Wisconsin is attracting national attention and big bucks.
Voters in the state are casting ballots for a state Supreme Court justice. The once obscure contest is grabbing national headlines and independent groups from the right and the left have spent more than $2.5 million dollars over the past two weeks on television commercials to try and influence the outcome of the technically non-partisan election.
The reason for all this attention and money is because the election has become a proxy battle in the fight over a controversial new law passed by state Republicans and signed by Republican Gov. Scott Walker last month that restricts the collective bargaining rights of public employee unions. That battle caused Democratic state lawmakers to flee Wisconsin and sparked weeks of protests at the state capitol building in Madison.
Up for re-election Tuesday is Justice David Prosser. Some unions and progressive groups are backing his more liberal challenger, assistant attorney general JoAnne Kloppenburg. The contest is the first state-wide election since the law was passed, and it's being seen as a referendum on the Republican governor's push to limit the collective bargaining rights of public sector workers.
But the election is also very important for another reason. The new law is being challenged in court, and it appears likely the case will reach the state supreme court. Prosser's seat is the swing vote. With Prosser on the bench, conservatives have a 4 to 3 advantage. If the more liberal Kloppenburg wins the election, the balance of power on the court shifts.
With all this in mind, it's no surprise that $3.4 million has been spent on television commercials on the election by independent groups over the past 90 days, with $2.5 million being spent just in the past two weeks, according to an analysis conducted by Kantar Media/Campaign Media Analysis Group, CNN's consultant on political and issue advertising. It's a record breaking infusion of cash for a state judicial election, as both progressives and conservatives try to influence the shape of the court.
"Due to the state of affairs, Wisconsin is now the tip of the spear for party politics, the local races are now attracting national attention and spending," says Evan Tracey, president of CMAG and a CNN consultant.
The biggest spender is the Great Wisconsin Committee, a progressive group that is supporting Kloppenburg and is opposed to Walker and the new law. The group has spent more than $1.2 million on ad time.
–Follow Paul Steinhauser on Twitter: @psteinhausercnn