Residents in Wisconsin will cast their votes Tuesday in a historic recall election that could force the state's Republican governor out of office.

The latest voter opinion surveys show Governor Scott Walker with a slight lead over his Democratic opponent, Milwaukee Mayor Tom Barrett, whom Walker defeated in the 2010 general election.

Shortly after taking office, Walker pushed through a law that sharply curtailed the right of most government employees to bargain for pay raises and other benefits, angering unions and Democratic activists and triggering several days of massive protests at the state capital in Madison. A grassroots campaign earlier this year gathered nearly one million signatures in a petition drive to force the recall election.

The recall effort in Wisconsin has attracted money and attention from both Republican and Democratic supporters across the country. Walker has raised $30 million dollars to fight off the recall, well above the $4 million raised by Barrett. Democrats are hoping to offset the Republican money advantage with a major grassroots effort to encourage voter participation.

The Wisconsin recall election is also seen as preview of the presidential race between incumbent Democratic President Barack Obama and likely Republican nominee Mitt Romney. Mr. Obama easily won Wisconsin in the 2008 presidential campaign, but a Walker victory could suggest that Romney has a chance to win the state in the November general election.

If he loses, Walker would become just the third U.S. governor to be forced out of office in a recall election, the most recent being California Governor Gray Davis' loss to Hollywood action star Arnold Schwarzenegger in 2003.

Also facing a recall in Tuesday's vote are Lieutenant Governor Rebecca Kleefisch and three Republican state senators. A fourth state senate seat is open after the incumbent resigned rather than face the recall.