Andy Manis, Associated Press
Wisconsin Supreme Court candidate JoAnne Kloppenburg, assistant attorney general, addresses her supporters in Madison, Wis., Wednesday, April 6, 2011, telling the audience the race to close to call. Kloppenburg faces incumbent Justice David Prosser.

WAUKESHA, Wis. — A stunning discovery of votes in Wisconsin could give the state's hotly contested Supreme Court race to the conservative incumbent in a race seen as a referendum on the Republican governor's union rights law.

Adding another twist, the county clerk who said she incorrectly entered vote totals has faced criticism before for her handling of elections. She also previously worked for a state Republican caucus when it was controlled by the very candidate who stands to benefit from Thursday's revelation.

The corrected totals gave Justice David Prosser a 7,500-vote lead over little-known liberal assistant state attorney general JoAnne Kloppenburg.

Opponents of the law that takes away nearly all public employee collective bargaining rights had hoped a Kloppenburg victory would set the stage for the high court to strike it down.