MILWAUKEE (AP) -- Supreme Court Justice Louis Butler has publicly conceded the race for his seat.

Challenger Michael Gableman won 51 percent compared to Butler's 49 percent Tuesday in a race that will go down as one of the nastiest in state history.

Liberal and conservative special interest groups spent millions of dollars on the race, largely on negative attack ads that blanketed the state's airwaves for weeks.

Butler says he doesn't regret not airing negative ads. He called the system broken because third party groups don't have to be held accountable for misleading ads.

He called on the Legislature to enact reforms, saying he hopes Wisconsin never has to see another race like this one.

Butler is the first incumbent Supreme Court justice to be ousted in 41 years.

Gableman takes office in August and will serve a 10-year term.

(Copyright 2008 by The Associated Press. All Rights Reserved.)