Whichever Democrat wins Tuesday’s recall primary in Wisconsin will have only a short four weeks to make the closing argument that Republican Gov. Scott Walker should be booted from office after 16 contentious months on the job.

For Milwaukee Mayor Tom Barrett, one of four Democrats in the running, a victory would set up a June 5 rematch of the 2010 race that Walker won by 5 percentage points. Walker easily defeated token opposition in the GOP primary Tuesday.

It was an election that failed to hint at the turmoil to come. Once inaugurated, Walker almost immediately joined with Republicans who had also retaken control of the Legislature to strip most state workers of their collective bargaining rights. The move blindsided Walker’s opponents, who proceeded to pack the state Capitol by the thousands for weeks of protest as Democratic lawmakers fled the state in an ultimately unsuccessful effort to block the newly minted governor’s plans.