"He spent four years being very strident about these positions, and now he can’t really decide what he wants to say about it because he knows how bad it is for women voters," Safar said.

Burke's campaign has run one ad attacking the governor's stance on abortion, but most activity has come from outside groups.

"I think that this is really the first time we’ve seen, in a statewide race, access to reproductive health care be a major issue," Safar said. "I think one reason for that is how bad Gov. Walker has been on it. He has … the most extreme anti-women’s health agenda that we’ve seen in Wisconsin. For many years, access to preventative health care, reproductive health care and comprehensive sex education has been a bipartisan issue, and people from both sides of the aisle have supported it. With Gov. Walker, all that changed, and all of a sudden access to birth control became a political issue for him."

Planned Parenthood is focusing its efforts on reaching drop-off voters who could play a key role in determining the election's outcome. The organization will continue to ramp up its outreach efforts over the weekend, Safar said.