Walker tackled the immovable obstacle head-on by limiting public-sector union collective bargaining, requiring unions to hold annual recertification votes (which would require 51 percent of members, not just those who vote, to approve) and prohibiting automatic payroll deduction of union dues. In short, he required the unions to prove that their members actually stand behind them.

The unions launched a scorched-earth campaign in response. Noisy protesters filled the State Capitol for weeks on end, vowing to make an example out of Walker. They proceeded to lose a series of special elections, culminating in Walker beating their recall effort by a larger margin than he had won the governorship by in the first place.

For a while, it looked like that a pyrrhic victory for Walker, since the unions had also succeeded in tying up the reforms in court. Two judges had stayed the reforms, and their future looked shaky. But on Friday, a three-judge appeals court panel upheld them, rejecting the unions’ argument that the reforms were unconstitutional because they excluded police and firefighters and therefore violated the equal-protection clause.