The Marquette Law School poll, released Wednesday, found Walker and Burke in a dead heat with both registered and likely voters. While 46 percent of registered voters said they would vote for Walker and 45 percent for Burke, among those who said they are certain to vote in November, 47 percent picked Burke and 46 percent Walker.The results are within the poll's margin of error.
Both candidates have strong support from their own parties, with only 3 percent of Republicans supporting Burke and 9 percent of Democrats Walker. The two are tied among independents with 44 percent backing Burke, who has gained among the critical bloc since a May poll, and 45 percent Walker.
Burke has a 7 percentage point advantage among women while Walker leads among men by 10 points. Married voters are more likely to support Walker, while those who are single, widowed or divorced prefer Burke.
Walker, soon after he took office in 2011, took on public employee unions in a battle over health-coverage contributions and collective bargaining rights. Democratic lawmakers left the state to try to scuttle votes on his proposals and thousands of protesters converged on Madison, the state capital, but Walker ended up getting his way.
The governor won the recall vote by a slightly bigger margin than he had in the 2010 election.
Burke, a former executive with her family's company, Trek Bicycle, has served as state secretary of commerce and is a member of the Madison school board.
Walker is one of a number of Republican governors who have lost ground with the voters. The most endangered appears to be Pennsylvania Gov. Tom Corbett, who is trailing his Democratic challenger, businessman Tom Wolf, by more than 20 points.
The Marquette poll surveyed 804 registered voters by telephone between July 17 and July 20. The margin of error is 3.5 percentage points among registered voters and 4.9 percent among likely voters.