Mark Janus just couldn’t take it anymore.

As a State of Illinois employee, he was forced to pay union dues that were being used to lobby for policies he didn’t believe in—more spending and higher taxes in a state already facing a budget crisis.

“The State of Illinois was in a really precarious financial position, and the union was advocating higher wages and benefits to the tune of about $3 billion,” Janus explained at a recent event in Chicago hosted by the Goldwater Institute and the Illinois Policy Institute.

“In order to pay for that, they were advocating for higher taxes. And I thought, well this isn’t right, because union people are taxpayers too. I just felt I had to do something.”

Janus took his case all the way to the U.S. Supreme Court and asked the justices to strike down the practice of forcing government workers to pay mandatory union fees. In June, the Court ruled in Janus’s favor by a 5-4 vote, deciding that public-sector employees do not have to pay for political activity with which they disagree in order to work in the job of their choice.

“With the Janus decision, more than five million government employees across 22 states are now free to choose for themselves whether they’ll give any money to a union,” says Jacob Huebert, a senior attorney at the Goldwater Institute. “Before, they either had to be union members or pay a fee that was almost as much as union dues in many cases. Now they don’t have to pay anything if they don’t want to.”

Despite the victory, Janus says his fight isn’t over.

“The unions are providing lots of misdirection and misinformation in so many different ways that people are getting confused,” Janus says. “And so that’s why I joined Liberty Justice Center and retired from the State of Illinois so I can hopefully help people that are in similar situations get out [of their union] or at least get their agency fees stopped.”

Public sector union employees aren’t the only Americans being compelled to pay for speech they don’t believe in. Lawyers in most states are forced to pay dues to a private bar association, and those fees are often used to lobby for public policies and ballot measures—in other words, political speech, just like in the Janus case. The Goldwater Institute is currently asking the Supreme Court to end these mandatory dues in a petition for certiorari in a case in which it’s representing a North Dakota attorney whose dues were used to oppose a ballot initiative he personally supported.

“Under the rule in Janus, of course the government shouldn’t be forcing lawyers to fund this just to be a lawyer,” Huebert says. “So we’re hopeful that later this month the Supreme Court will say ‘yes’ to the petition and take the next step to end these mandatory fees that lawyers are forced to pay.”