The Supreme Court ruled 5-4 Wednesday that state government workers cannot be forced to pay so-called "fair share" fees to support collective bargaining and other union activities.

The case specifically examined union fees paid by non-members, and the conservative majority determined that a union's contract negotiations over pay and benefits were inextricably linked with its broader political activities.

The key plaintiff was Mark Janus, an Illinois state employee, who pays about $550 annually to the powerful public-sector union known as AFSCME. While not a member of the union, he is required under state law to hand over a weekly portion of his paycheck -- which he says is a violation of his constitutional rights.

On "Fox & Friends," Janus said he shouldn't be forced to pay money to a union whose politics and policies he may disagree with, arguing it violated his right of freedom of association guaranteed by the First Amendment. 

Trump Rips Maxine Waters at ND Rally: 'Imagine If I Said Those Things'

Trump's Judicial Adviser Talks Potential Replacements for Justice Kennedy

"If people want to voluntarily join a union and they want to voluntarily pay the dues, I think that's absolutely good for that individual and that union," Janus said. "But why should I as a condition of employment be forced to pay a fee in order to just work in a public sector area?"

Janus' attorney, Jacob Huebert, said it was a clear violation of Janus' First Amendment rights, and the court's ruling could have a significant impact on the broader American labor union movement.

"In some places, workers probably like their union and lots of them will join, and the unions won't lose much money," Huebert said. "But maybe in other places where unions have taken the workers' money for granted and haven't been very responsive, people will opt out a lot. But we'll see. It just depends on the choices that people make now that they're free to make them."

The swing vote in the case was cast by Justice Anthony Kennedy, who later on Wednesday announced he will retire on July 31.

Sen. Cruz: 'We Should Confirm SCOTUS Pick Before Election', Suggests Mike Lee

Schumer Demands Congress Use 'Biden Rule' in Choosing Kennedy Replacement

Wallace: Replacing Justice Kennedy Will Be 'Biggest Moment of the Trump Presidency'

'Admit How Wrong You Were': Hannity Rips 'Never-Trumpers' as Second SCOTUS Spot Opens