Wisconsin's election chief says he expects the unofficial vote totals in the state Supreme Court race to change when local election officials verify the counts, as opponents of Republican Gov. Scott Walker say the results send a clear message about their unhappiness with his controversial limits on union power.

Kevin Kennedy, head of the state's Government Accountability Board, said Wednesday that there will be changes in the totals because "this is a very human-driven process. We expect mistakes."

Little-known attorney JoAnne Kloppenburg declared victory over incumbent state Supreme Court Justice David Prosser with just a 204-vote margin out of nearly 1.5 million cast.

Kennedy says the earliest he would expect a recount request to be able to be made would be late next week. As long as there is no court challenge along the way, Kennedy says he expects the recount would be completed by May 15.

With 100 percent of precincts reporting, Kloppenburg had 740,090 votes, or 50.01 percent. Prosser had 739,886 votes, or 49.99 percent.

Kloppenburg issued a statement thanking Prosser for his service and vowing to be an impartial judge. Prosser's campaign didn't immediately return a message seeking comment on whether he would seek a recount. The latest such a request could be made is April 20.

Counties must start to canvas the vote on Thursday and they have until April 15 to turn in the results. Once the county's last report is filed, a recount can be requested within three business days.

That makes April 20 the latest such a request could be made. If the county reports come in sooner, the deadline to ask for the recount would be pushed up as well.

The winner will serve a 10-year term.