The governor of the U.S. state of Wisconsin faces a possible special election to remove him from office. Opponents are angry at Governor Scott Walker for backing legislation earlier this year that restricted the collective bargaining rights of public employees. They are now trying to gather enough signatures to force a recall vote.

On a cold morning in Madison, Wisconsin, a steady stream of vehicles pulls off to the side of the road, greeted by clipboard-armed volunteers like Ray.

"I"ve organized a group of about 80 people," said Ray. "Most of us are retired teachers and we"ve set up what is called a drive-through. It's kind of like a McDonalds' drive through where people will drive in, and sign our petition to recall Governor Scott Walker."

Ray didn't want to use his last name for fear of retribution for participating in the recall effort. but he says his drive-through petition is working.

"This is our seventh day, and we are at about 2,400 signatures right now," he said. "We are getting a little over 400 a day."

A political action group called United Wisconsin is spearheading the effort to recall Governor Walker. And the group's director, Meagan Mahaffey, says the more than 540,000 signatures needed to trigger the recall vote are within reach.

"The first 48 hours, over 50,000 people had signed the petition to recall Walker," she said. "In the first 96 hours, we were at over 105,000 petitions that had been in our office in our hands to recall Walker. Over 20,000 people have gone online to download the petition and more and more do it every day."

The uproar began last winter, when Walker, a Republican, moved to balance the state budget with legislation that curbed collective bargaining rights for state employees. The bill passed after lengthy procedural roadblocks, and also requires public employees to contribute more towards their benefits.

"What this represents is a threat to the union movement within the state, and because the unions are so important to supporting Democrats, a threat to the Democratic Party as well," said Professor Charles Franklin.

University of Wisconsin, Madison, Political Science Professor Charles Franklin says the recent rejection of similar legislation in Ohio was a victory for the labor movement. But he says there are stark differences between the two states.

"Ohio had a very clean vote, either for or against this specific bill that was passed," he said. "Here in Wisconsin it's not just about that bill, it's about the governor as a person, it's about his other policies."

Governor Walker is fighting back against his opponents, using TV ads that also appear on YouTube to send the message that his controversial legislation is working.

"I think this sets the theme," said Franklin. "That ad stresses how school districts have been able to deal with their budget cuts and issues because of the flexibility they"ve received with the changes in these union rules."

Even if Walker's political opponents gather enough signatures to force a recall election, that does not necessarily mean he will be forced from office. Democrats also have to find a candidate who can beat the Republican incumbent in that special election.