(AP) WASHINGTON – The strength of President Barack Obama’s bid for a second term faced a key test Tuesday in a Wisconsin election to decide whether the Republican governor of the Midwestern state, a hero of the deeply conservative tea-party movement, should be ousted more than two years early.

At press time, results show Walker leading with 53% of the vote to 47% for Tom Barrett, his Democratic challenger.The recall election marks just the third time in U.S. history that a state governor has been challenged midterm. What’s more, Wisconsin is a key swing state in the November presidential election. It is seen as leaning toward Obama, but Tuesday’s vote could show an inclination to flip toward Republican challenger Mitt Romney.

The effort to unseat Gov. Scott Walker is rooted in Wisconsin’s labor union movement and the Democratic rank-and-file, both profoundly angered over his budget-cutting policies. If Walker successfully defends his leadership, it would be a major boost for already highly motivated tea party voters, who want smaller government, lower deficits and tax cuts.

With the economy the top issue in the presidential election, a victory for Wisconsin conservatives would underscore Romney’s strength nationwide. He has endorsed budget-slashing, tax-cutting tea party fiscal plans at the national level.

Most polls show Walker with a slight advantage over Democratic challenger Tom Barrett, a former member of the U.S. Congress and Walker’s opponent in the 2010 governor’s race. Defending Walker has become a major cause for national Republicans and outside interests who back his pro-business, anti-union positions.

Walker said Monday he expects a close race and he’s focused on turning out voters who supported his efforts to take on public-employee unions.

Barrett, currently the Milwaukee mayor, has found support from top Democratic political figures, including former President Bill Clinton and party chairwoman Debbie Wasserman. Obama, however, has not intervened on his behalf, perhaps not wanting to chance being directly associated with what might be a losing effort with five months remaining before the presidential election.

White House press secretary Jeff Carney was asked during a briefing Monday why Obama wasn’t campaigning for Barrett.

“The president supports him, stands by him,” Carney said, adding that Obama hopes Barrett prevails.

Walker stripped public employee union members of most of their collective bargaining rights and forced them to pay more for health insurance and pension benefits. Angry civil servants, from school teachers to firefighters and police, backed a petition drive that collected sufficient signatures to force the recall vote.

“Now it’s our turn to speak,” an exuberant Barrett told campaign workers Monday. “We the people of the state of Wisconsin are going to reclaim our future.”

The campaign surrounding the vote also is producing fuel for opponents of a 2010 U.S. Supreme Court ruling that opened the door to unlimited corporate campaign spending. The only provison requires that corporate donations go to a committee that does not coordinate directly with the candidate or his or her campaign organization.

The recall election has been unlike anything seen before in Wisconsin, with at least $62 million spent by the candidates and outside groups so far. Walker was the top spender at $29 million, with Barrett’s campaign spending about $4 million. Outside groups have spent $21 million and issue ad groups that don’t have to disclose their spending have put in at least $7.5 million.

The recall may have started over collective bargaining, but the overriding issue has become job creation. Walker promised in 2010 to create 250,000 jobs over four years, but he is not on pace to meet that goal. How far afield he is depends on what set of numbers are used to measure his promise. Monthly jobs figures, based on a survey of about 3.5 percent of Wisconsin employers, show job creation has been flat since Walker took office. But a combination of data, including 2011 numbers derived from a more comprehensive census of employers, shows about 33,000 new jobs have been created in Walker’s term.

While the Walker-Barrett race is in the national spotlight, also on the ballot are recall elections for the Republican lieutenant governor and four Republican state Senate seats. If Democrats win any one of those seats, they will hold a majority in the Senate for the first time since 2010 and could obstruct any further advancement of Walker’s agenda if he wins.

The only other two governors to have faced a recall vote lost, most recently California Gov. Gray Davis in 2003.

A defeat for Walker would badly damage a political career that until now had looked on course to national prominence. A victory would cement his place as a national tea party hero with a rosy future in a Republican party that is evolving more and more toward the hard right on the American political spectrum.