Do some simple figuring. Union households gave 40% of their vote to Walker.
A majority of unionized workers are government employees. Other than police and firemen, who were not involved in the controversial statute, it is probably a fair guess that government employees, especially the teachers, voted overwhelmingly, close to unanimously, against Walker, and overall, that government employee union households voted somewhere around 80% for Barrett. It is therefore also a simple deduction that at least half of industrial union households voted FOR Walker. The guys brewing beer and making bratwurst, or Kohler fixtures, the people you think of as labor union guys, were voting for Walker.