That's the latest in a series of polls showing Wolf, a former state Revenue Secretary under then-Gov. Ed Rendell, leading Corbett by 20 points or more.
Fifty-four percent of all the registered voters in the poll expect Wolf to win the Nov. 4 general election while just 19 percent expect Corbett to pull out a victory. Just one in four voters think Corbett deserves a second term.
While the poll shows Corbett doing better with Republicans than he has in previous surveys, it also shows some in his party giving up on their candidate.
"He's losing one in five Republicans," Madonna said. "And he's losing 2-to-1 among independents. That's not a recipe for victory."
The $29.1 billion budget, approved by the state Senate and House along mostly party-line votes, would increase spending for public education. Madonna says Corbett's record on the issue is still a reason voters cite to reject him.
No governor has lost re-election since the state Constitution was changed in 1968 to allow for a second term.
Madonna researched polls going back to that era and found today's poll is the first in the state in which the issue listed most often by registered voters - 23 percent of them - as their top concern was education.
"That's how significant this has become," Madonna said.
Madonna said Corbett faces a daunting task of convincing voters that he needs a second term to finally accomplish his goals.
"He has to change the dynamic in some way," Madonna said. "He's got to figure out how to get the voters to give him a second look."
Wolf, who won the four-way May 20 Democratic primary election with a wave of self-financed campaign commercials, is leading Corbett in every corner of the state, including Corbett's home base of Allegheny County. Wolf holds a 12-point lead there.
Corbett on Monday issued a statement after the budget votes, saying he is "withholding" his signature "while I deliberate its impact on the people of Pennsylvania." He said the budget does not address the state pension reforms he had been pushing.
The state House yesterday sent pension-reform legislation back to a committee for further consideration, an apparent sign that no immediate action will be taken on the issue.
Corbett has 10 days to sign into law or veto the budget legislation. It becomes law after 10 days if he takes no action on it.
On Twitter: @ChrisBrennanDN