MADISON, Wis. (AP) -- Wisconsin Democrats and their allies who are trying to take out Republican Gov. Scott Walker have invested all their hopes in Mary Burke, a Harvard-educated political newcomer whose father started Trek Bicycle when she was a teenager.
For Democrats and their friends in organized labor, this race is personal. They mean to avenge Walker's evisceration of union power as he builds his resume for a possible presidential run.
But for Burke, the campaign also poses an awkward challenge: She can't talk too stridently about her opponent's most provocative actions for fear of alienating independent voters, many of whom supported both Walker's union crackdown and President Barack Obama's re-election bid. And they will decide this contest, too.
That forces Burke to talk about supporting unions, but not to the point of overturning the law that took away nearly all collective-bargaining rights for public workers. She's even spoken in favor of the law's requirement that workers pay more for their health insurance and pension benefits.
"She flirts with that, and I think that's the best anyone is going to come up with in a campaign," said John Matthews, president of the Madison teachers union.
Walker and Republicans have successfully convinced voters that the law was necessary, making it difficult for Burke to speak out too strongly against it, Matthews said.
Such delicate maneuvering would be a test for even a seasoned office seeker. But this is Burke's first statewide campaign after working as a state commerce secretary and a Trek executive. The 54-year-old launched the bid less than two years after being elected to her first position, a seat on the Madison school board.
Walker pushed his signature legislation through the Republican-controlled Legislature in 2011, effectively ending collective bargaining for most public workers. Ever since, opponents have been searching for the right candidate to challenge him.
After failing with Milwaukee Mayor Tom Barrett in the 2012 recall, their hopes now rest with Burke, a businesswoman who's been crisscrossing Wisconsin introducing herself to voters as an alternative to Walker, the only governor in U.S. history to survive a recall.
Burke is hitting traditional Democratic issues like job creation and gay marriage instead of focusing on undoing the union law that attracted protests as large as 100,000 people and catapulted Walker onto the national stage.
Both sides seem to have concluded that the union law is off the agenda. Even the very unions hurt most by Walker's reforms are making their case against the governor based on other factors.
That's largely because Walker and Burke are going after the same 7 percent to 10 percent of voters that polls show are undecided. The so-called "Walker-Obama" voters are people who voted against recalling Walker in 2012 but said in exit polls that they intended to vote for Obama that fall.
Walker won the recall by 6.8 percentage points. Obama carried Wisconsin by 6.9 points.
A poll conducted just before the Walker recall showed that a majority of voters preferred to keep the union law rather than undo it, including 53 percent of the key independent-voter demographic.
Democrats learned from the recall that they can't win on the union issue alone. In fact, the recall candidate who promised to veto any state budget that did not undo the law could not even win the Democratic primary that year.
Burke, who declined to comment for this story, has been careful to articulate her support for collective bargaining and opposition to Act 10, but she won't promise to work on repealing it.
Burke's campaign website does not even mention her position on the union law, instead touting her jobs plan, her support for gay marriage and her opposition to school vouchers. A news release announcing her endorsement by the unions representing Wisconsin teachers, state employees and others failed to mention her view on the law known as Act 10.
"As a whole, we believe she wants what we want," said Betsy Kippers, president of the state teachers union. "There are many issues that are important to our members, not just Act 10."
Voters whose most important issue is Act 10 have already decided whether they're with Walker or Burke, said Democratic state Sen. Tim Cullen. He described it as a "second-tier" issue now, behind others like jobs and the economy.
Act 10 required public workers -- including teachers and most state employees -- to pay more for their health insurance and pensions. It also took away their ability to collectively bargain over workplace-safety, vacations, seniority rights and a myriad of other issues in union contracts. Bargaining is now limited to general wage increases that do not exceed inflation.