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A new Marquette Law School poll in Wisconsin shows Milwaukee Mayor Tom Barrett within a single percentage point of Republican Gov. Scott Walker in a head-to-head match-up of the recall election.

Barrett, who ran against Walker in 2010 and was defeated by a margin of 5 percentage points, has a 47-46 lead over Walker among all registered voters. However, when the pool is narrowed to likely voters, the lead flips, and Walker has 1 percentage point over Barrett of 48 percent to 47 percent.

Barrett seems poised to be the Democrats' choice to battle Walker in the June 5 recall election. With less than a week until the May 8 Democratic primary, the Marquette poll shows Barrett with a 38-21 lead over former Dane County Executive Kathleen Falk-a big increase from the last Marquette poll in March, which showed Barrett up by only 7 points.

The numbers represent a strong improvement for Barrett among both Democrats and Republicans.

"Despite Barrett's late entry into the race, he has improved his position both among Democratic primary voters and in the general recall contest against Walker. Barrett trailed Walker by 6 percentage points in January but cut that to two points in March. The contest is now essentially a tie," writes Marquette Law School poll director Charles Franklin.

With a little over a month until election day, donors in both parties are opening up their wallets to help with the cause.

Figures released earlier in the week showed that Walker had raised a staggering $13 million from mid-January until the end of April. Walker has raised more than $25 million to fight his recall election, undoubtedly benefiting from a quirk in Wisconsin election law which allowed him to raise unlimited funds during the time signatures for his recall were being gathered and approved.

Some 66 percent of the $13 million he took in during the first few months of 2012 came from donors living outside of Wisconsin.

Barrett has actually been out-fundraised by Democratic challenger Kathleen Falk, who brought in $977,059 to Barrett's $831,508. However, $332,162 of Falk's money has come from outside spending groups, while almost all of Barrett's money has come from individual donors. Barrett also entered the race in March, almost three months after Falk.

Walker is the first governor in Wisconsin state history to face a recall, mainly over his push to strip some state unionized workers of their collective bargaining rights. If he is defeated, he will be the third governor in U.S. history to be recalled.