Before Wisconsin’s Democrats take their fight to Scott Walker in June, they will be fighting amongst themselves.

Several public unions that have already backed former Dane County Executive Kathleen Falk’s bid to become Wisconsin’s next governor are suddenly facing an uncomfortable scenario: Their favored candidate may not survive the Democratic primary now that Milwaukee Mayor Tom Barrett has entered the political steel cage.

Barrett, who lost to Walker in the 2010 race for governor, announced last week that he would jump into the race to oust the Republican, who was targeted after championing a law that curtailed public workers’ collective bargaining rights. Barrett made a campaign stop in Rhinelander Thursday during a whirlwind tour of the Northwoods, and answered several inquiries, including his plans to win the support of major unions that are already supporting Falk. Barrett has at times clashed with unions while leading the state’s largest city over education and budget issues. He also refused to promise, unlike Falk, that he would veto a state budget if it didn’t restore collective bargaining rights, prompting unions to ask him to stay out of the recall race.

“I am very confident that the union leaders will understand that I am the right candidate to work with them,” said Barrett. “I promise to sit down and work with the unions, just like I always have in Milwaukee. You need to get everyone to agree to talk before you can start working toward a solution.”

Barrett has picked up many high-powered political endorsements of his own in the last two weeks. Former U.S. Congressman Dave Obey and 12th District State Senator Jim Holperin were on hand in Rhinelander to support Barrett Thursday, and others such as U.S. Senator Herb Kohl and former U.S. Congressman Steve Kagen have pledged their support in recent days. The primary, which will pit Barrett against Falk and additional candidates Doug La Follette and Kathleen Vinehout, is scheduled for May 8, with the general election on June 5.

For the last several months, Barrett has essentially been running two campaigns: first to be re-elected as Milwaukee’s mayor (he won overwhelmingly on April 3,) and for governor in the recall election against Walker. While Falk has already been campaigning for months, Barrett instead chose to wait until the state’s Government Accountability Board certified the recall effort against Walker before jumping into the race, explaining it as the “ethically correct” choice.

“I announced my intentions six hours after the GAB certified the recall,” Barrett said. “I was certainly prepared for the recall, but in my mind, we did it right. I wasn’t going to run for a position that wasn’t open.”

During his stop, Barrett compared his campaign to the movie “Groundhog Day” in which Bill Murray’s main character relives the same day over and over. In addition to Barrett’s loss to Walker 16 months ago, he also ran against and lost to Jim Doyle in the Democratic gubernatorial primary in 2002. Barrett said he was proud of the campaign he ran against Walker in 2010, but explained that he got caught up in the “Tea Party Tornado” that saw many Democratic stalwarts, including longtime Wisconsin Senator Russ Feingold, lose their seats.

“The year I ran for Governor was one of the worst times in this state’s history to be a Democrat,” said Barrett. “Now that people have seen what can happen in this state under Republican control, it’s now a much better proposition to run for office as a Democrat.”

Holperin, who announced last month that he would not seek another term as the 12th District State Senator, said that he was supporting Barrett because he viewed the Milwaukee mayor as a “consensus builder.” “Tom is someone who can work with both sides and find a win-win,” said Holperin. “I believe that it is very important, with our current political climate in Wisconsin, that we elect a governor that can work with everyone.”

Obey said he was supporting Barrett because he believes Barrett stands the best shot of unseating Walker in June.

“The person chosen to run against Walker will face a barrage of attacks paid for by Walker’s wealthy contributors,” said Obey. “Tom Barrett can weather those attacks.”

Editor Craig Mandli is available at cmandli@jrn.com.