Updated 3:40 p.m. - Wisconsin Gov. Scott Walker is virtually tied versus his prime Democratic challenger in a June 5 recall election, according to a new poll released Wednesday.
A Marquette University Law School poll found that Walker, whose efforts to overhaul collective bargaining laws in his state prompted the recall, leads Milwaukee Mayor Tom Barrett (D) by a single point among likely voters, well within the margin of error. (Among registered voters, Barrett leads 47-46 percent.)
If the recall election were held today, 48 percent of likely voters said they would choose to retain Walker, versus 47 percent who said they would pick Barrett, the Democratic challenger to Walker in the 2010 general election.
Barrett also leads his main challenger in the Democratic primary, former Dane County Executive Kathleen Falk, heading into next week's primary. Thirty-eight percent of Democratic primary voters prefer Barrett, while 21 percent would vote for Falk; that's a wider advantage for Barrett than in a late March poll.
If Falk, who enjoys the support of organized labor, were to somehow win the primary, she would face a somewhat tougher race versus Walker. Forty-nine percent of likely Wisconsin voters would support Walker in a recall versus Falk, who would win 43 percent of the vote.
The Marquette poll also tested the general election matchup this fall between President Obama and Mitt romney. Obama leads at 51 percent of likely voters to Romney's 42 percent share.
The poll, conducted April 26-29, 2012, has a 3.8 percent margin of error for the full sample. Democratic primary voters had a margin of error is 4.7 percent, and the margin of error for "likely voters" is 4.2 percent.
Update: The most recent figures from NBC's ad-tracking sources indicate that Walker and supportive groups have spent a total of $16.6 million in favor of Walker, while Democratic and labor groups have spent $6.3 million.