Wisconsin Gov. Scott Walker (R) enjoys a 7-point advantage over Democratic challenger Tom Barrett among likely voters in Tuesday's recall election.

Darren Hauck / Reuters

Republican Wisconsin Gov. Scott Walker debates with Democratic challenger and Milwaukee Mayor Tom Barrett before the start of the debate in Milwaukee.

Fifty-two percent of likely voters said they would vote to retain Walker, according to a Marquette Law School poll released Wednesday; 45 percent of likely voters said they would support Barrett, the mayor of Milwaukee.

The poll suggests that Walker is heading toward victory on Tuesday, which would deliver a stinging rebuke to Democrats and members of the labor community who had sought the first-term governor's removal after he pushed a controversial bill curbing collective bargaining rights for many public employees through the Wisconsin state legislature.

The Marquette poll has been tracking the trajectory of the recall election for the better part of this spring. The survey found Walker and Barrett locked in a virtual tie ahead of the Democratic primary in early May, though a May 16 poll reflected Walker opening an advantageover his Democratic opponent.

Labor groups and Democrats supportive of Barrett have been circulating a number of internal polls over the past week showing a closer race than many outside observers have expected.

In the meanwhile, Walker and Barrett have debated, and the campaign has evolved into a rather pointed battle between the two candidates, who squared off in the initial 2010 gubernatorial contest.

Barrett has demanded that Walker release records associated with a criminal investigation into former aides, while Walker has barnstormed the state to brag of positive economic indicators that, he contends, were made possible in part by his initial collective bargaining reforms.

Thousands of dollars in outside spending have also flooded Wisconsin airwaves in this high-stakes contest. Republicans are hoping an organization forged in Walker's 2010 election and last year's state Senate recalls carries the day; Democrats are meanwhile enjoying the assistance of organized labor.

Democratic National Committee (DNC) Chairwoman Debbie Wasserman Schultz was in Wisconsin on Wednesday to help with fundraising, and Maryland Gov. Martin O'Malley, who heads Democratic gubernatorial campaign efforts, will be in the state this weekend.

A series of Republican heavyweights, including New Jersey Gov. Chris Christie, have also campaigned in support of Walker, and Republican National Committee Chairman Reince Priebus will be in his native Wisconsin this weekend, too.

The poll, conducted May 23-36, has a 4 percent margin of error.

Wisconsin Gov. Scott Walker has opened up a 6-point lead over Democratic challenger Tom Barrett ahead of a closely-watched June 5 recall election.

Fifty percent of Wisconsin's likely voters said in a Marquette Law School Poll that they would support retaining Walker versus 44 percent of likely voters who said they would instead elect Barrett, Walker's challenger in the 2010 general election who will again face Walker after having won last week's Democratic primary.

The poll would seem to reflect what had been an anecdotal sense that Walker has opened up an advantage in the few weeks before the recall election.

A target of Democrats and organized labor since pushing a dramatic reform of collective bargaining rights for public employees through the Wisconsin state legislature, Walker has raised millions more than his challengers in order to fend off the recall effort.

If Walker were to win, it would be a symbolic victory not only for his efforts to curb labor rights, but also for a series of other Republican governors who have embarked upon the same path. It would also be a disappointing setback for organized labor.

It could also help put Wisconsin in play for this fall's general election between Mitt Romney and President Obama.

Among likely Wisconsin voters, Obama and Romney were tied at 46 percent in a hypothetical November matchup.

A poll preceding the Democratic primary in Wisconsin had showed Barrett and Walker virtually tied in the gubernatorial recall, suggesting that the tide might have turned back toward Walker in the weeks since then.

The Republican governor had a 50 percent approval rating, according to the most recent Marquette poll, versus 46 percent of Wisconsinites who disapporove of the way he is handling his job.

The remainder of the recall campaign is still expected to be a hard-fought campaign, with millions in ads sponsored by outside groups on both sides. But reflecting the stakes of the race, and prevailing sentiment in Washington, state Democrats had to complain publicly about a lack of support from the Democratic National Committee before eliciting a promise to help raise funds.

The Marquette Law School poll, conducted May 9-12, has a 4.1 percent margin of error for the sample of likely voters.

Wisconsin Democrats nominated Milwaukee Mayor Tom Barrett as their candidate versus incumbent Gov. Scott Walker (R) in the June 5 election seeking Walker's recall. 

The Associated Press projected Tuesday evening that Barrett had won the Democratic nomination over rival Kathleen Falk, a who had enjoyed the support of organized labor and the state's progressives. 

Barrett's victory sets off a June 5 election versus Walker, a national Republican figure since his controversial effort to overhaul Wisconsin's collective bargaining laws for public employees shortly after assuming office in 2011. 

The contest will mean a rematch between Walker and Barrett; they fought each other in the 2010 general election, and Walker won the governorship with just above 52 percent of the vote. 

A Marquette University Law School poll last week pegged the early June recall election as a veritable dead heat between Barrett and Walker.