Updated

Public-employee unions in Wisconsin have experienced a dramatic drop in membership -- by more than half for the second-biggest union -- since a law championed by Republican Gov. Scott Walker sharply curtailed their ability to bargain over wages and working conditions.

Now with Mr. Walker facing a recall vote Tuesday, voters will decide whether his policies in the centrist state should continue -- or whether they have gone too far.

The election could mark a pivot point for organized labor.

Mr. Walker's ouster would derail the political career of a rising Republican star and send a warning to other elected officials who are battling unions. But a victory for the governor, who has been leading his Democratic opponent in recent polls, would amount to an endorsement of an effort to curtail public-sector unions, which have been a pillar of strength for organized labor while private-sector membership has dwindled.

That could mean the sharp losses that some Wisconsin public-worker unions have experienced is a harbinger of similar unions' future nationwide, union leaders fear. Failure to oust Mr. Walker and overturn the Wisconsin law "spells doom," said Bryan Kennedy, the American Federation of Teachers' Wisconsin president.

Wisconsin membership in the American Federation of State, County and Municipal Employees-the state's second-largest public-sector union after the National Education Association, which represents teachers-fell to 28,745 in February from 62,818 in March 2011, according to a person who has viewed Afscme's figures. A spokesman for Afscme declined to comment.

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