"Do we want a governor who has divided this state like it has never been divided before?" Barrett asked supporters after winning the Democratic gubernatorial primary Tuesday night with 58 percent of the vote. "Do we want a governor who has caused this state to lose more jobs than any other state in this country?
"This race is not about the past. It is not about the past," Barrett said in Milwaukee. "It is about the future of Wisconsin."
Barrett beat fellow Democrat Kathleen Falk, a former Dane County executive who had received more than $4 million in support from outside groups as labor's preferred candidate.
The 58-year-old Milwaukee mayor lost to Walker in the 2010 gubernatorial race by 6 percentage points and is now in a statistical dead heat with him, a late-April poll by Marquette University Law School indicated.
The historic recall election against the embattled Republican governor is scheduled for June 5.
Walker, who has battled public employee unions since taking office last year, easily brushed off a challenge by Arthur Kohl-Riggs, a liberal Walker critic and frequent state Capitol protester who ran as a Republican.
"Do we want to go back to the days when a handful of special interests controlled our state and local governments? No," Walker told supporters.
"Instead, we put in place reforms that rightfully put the hardworking taxpayers of Wisconsin in charge. We're not going backwards. We're going forward," Walker said.
Walker had framed the recall as damaging to the state's economic health, particularly job creation.
He told the Milwaukee Journal Sentinel last week if he loses, it will open the door to "recall ping-pong."
"It will go back and forth. I don't think that's just bad for elections -- it's bad for jobs," he said.
If Walker loses in June, it would be only the third time in U.S. history a governor has been recalled from office.
The last time was in 2003, when California Democrat Gray Davis was recalled and succeeded by Republican Arnold Schwarzenegger.