Thursday’s 5-2 ruling is a victory for Walker, who is considering a 2016 run for president and is seeking re-election this year. It also marks the end of the three-year legal fight over the union rights law, which prohibits public worker unions for collectively bargaining for anything beyond base wage increases based on inflation. A federal appeals court twice upheld the law as constitutional.

The high court ruled in a lawsuit filed by the Madison teachers union and a union representing Milwaukee public workers. They had argued that the law, which came to be known as Act 10, violated workers’ constitutional rights to free assembly and equal protection.