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Wisconsin voters in Tuesday’s recall election are essentially split on the changes made to collective bargaining for state workers.

Preliminary exit polls conducted for the Associated Press show about half of the voters approve of the changes made under GOP Gov. Scott Walker, who is facing the recall vote for removing the bargaining agreements for most state employees represented by unions.

About 4 out of 10 voters on either side of the issue said they felt strongly about the changes. Roughly 50 percent gave a favorable opinion of unions for government workers. Roughly 40 percent had an unfavorable view of unions.

The majority of voters think recall elections should be allowed in at least some cases, though most thought they are appropriate only in cases of official misconduct.

Voter turnout is reported to be strong. There have been no reports of problems with polling machines but some unconfirmed reports of voting irregularities.

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The campaigns for Walker and Democratic challenger Tom Barrett have spent the final days in a furious effort to get voters to the polls and sway what few undecided voters remain, after nearly 18 months of TV ads, candidate appearances and other campaign efforts.

Walker said voting day came almost as relief. He also said he thinks most people are happy to have the election over and "want to have their TVs back" following weeks of political ads.

Barrett applauding voters for turning out in force and for being prepared to wait a while to cast their ballots. He also said he considers the long lines "a very encouraging sign."

“There is no sign of voter fatigue,” Wisconsin Republican Party spokesman Ben Sparks told Fox News.

He also said Democrats have less voter enthusiasm because “it’s tough to get intense about a campaign that says: I’m not Walker.”

A key question will be whether Democrats can turn out voters in force, as the unions did during the protests last year. It could come down to how the parties do in swing counties in the western part of the state.

The effort to recall Walker began shortly after he was elected in 2010 and began cutting the state’s huge budget shortfall by holding down taxes and removing collective-bargaining rights for unions representing state employees.

Democrats and unions argued that Walker had gone too far, then helped organize massive statehouse protests and gather 900,000 signatures for the recall vote that pits the governor against 2010 opponent Barrett.

Most polls have Walker leading Barrett by 7 percentage points.

Both parties have poured huge money into the state, including $1.5 million from the Republican Governors Association for a last-minute, get-out-the-vote mailer that reached more than 3 million people.

More than $60 million was spent on the election.

Though polls close this evening, the impact of the vote is expected to carry into the November elections.

Republicans argue a win will largely prove that voters across the country want their elected officials to keep states living within their means and that taxing residents or businesses continues to slow the economy.

They also say that a Walker win would result in GOP presidential candidate Mitt Romney becoming the first Republican candidate to carry Wisconsin since Ronald Reagan in 1984. A loss for Walker will lead others to say the presumptive Republican nominee should give up on the key swing state.

Though Romney visited the state with Wisconsin GOP Rep. Paul Ryan earlier this year, President Obama did not travel to Wisconsin to campaign for Barrett, though he tweeted his support Monday night.

"It's Election Day in Wisconsin tomorrow," the president tweeted late Monday, "and I'm standing by Tom Barrett. He'd make an outstanding governor."

Barrett said he's not disappointed that Obama didn't do more.

He told CNN on Tuesday morning that he doesn't feel ignored by Obama -- "not one bit."

Barrett also said people want to make the recall vote a national election, but he thinks it's really more about Wisconsin, its people and jobs.

He and Walker worked in a flurry of last-minute stops in the campaign's final days, all too aware that turnout will be critical.

"I've been villainized for a year and a half. We've faced a year and a half of assaults on us. My opponent has no plans other than to attack us," Walker said at a campaign stop Monday, claiming that his agenda has put the state on the right economic track.

Since taking office, Walker has reduced the state budget and lowered the unemployment rate.

Walker said he is focused on capturing voters who have supported him in taking on public-employee unions, while Barrett is trying to capitalize on the anger over Walker's conservative agenda that began building almost as soon as he took office in January 2011.

"Gov. Walker has divided the state, but we will never allow him to conquer the middle class," Barrett said at an afternoon appearance. He added: "This started out as a grassroots movement and it's going to end as one."

The recall petition drive couldn't officially start until November, months after Walker signed the union changes into the books, because Wisconsin law requires that someone must be in office for at least a year before facing a recall.

Now, Walker stands in unique company: He is only the third governor in U.S. history to face a recall vote. The other two lost, most recently California Gov. Gray Davis in 2003.

Many ballots have already been cast through absentee voting.

Walker, the 44-year-old son of a minister, has remained unflappable throughout the campaign, just as he was during the massive protests that raged at the Statehouse for weeks as lawmakers debated his proposal. Along the way, he's become a star among Republicans and the most successful fundraiser in Wisconsin politics, collecting at least $31 million from around the country since taking office. That obliterated his fundraising record of $11 million from 2010.

Much of the money for the race has come from out of state. About $63 million has been spent on the race so far, including money from the RGA, Americans for Prosperity and the National Rifle Association. The majority of Walker's donations are from people outside Wisconsin.

Democratic groups -- including those funded by unions, the Democratic Governors Association and the Democratic National Committee -- have poured in about $14 million, based on a tally from the government watchdog group the Wisconsin Democracy Campaign. Barrett's $4.2 million in donations, meanwhile, were mostly from inside Wisconsin.

The race has attracted some big names on both sides. Republican New Jersey Gov. Chris Christie appeared on behalf of Walker, while former President Bill Clinton came out for Barrett in the race's final days.

Walker won't be the only politician up for recall Tuesday. His lieutenant governor, Rebecca Kleefisch, and three Republican state senators also face recall votes Tuesday. A fourth state Senate seat will be determined after the Republican incumbent resigned rather than face the recall.

The Associated Press contributed to this report.