This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

In the shadow of the 2016 presidential election, the Supreme Court will hear a case next term that could determine whether public sector non-union employees can be forced to pay mandatory dues for collective bargaining.

It is an issue of critical importance to unions who are fearful the conservative justices on the Supreme Court are poised to overturn court precedent and weaken union coffers. And weakening traditionally left-leaning organized labor could have the impact of diminishing a key Democratic constituency while the 2016 election is in full swing.

The case, Friedrichs v. Wilford, pits public unions against conservative groups seeking to dilute their power. Precedent holds that while a union can’t demand money from non-union workers for political spending, it can require those employees to pay for workplace bargaining.

The challenge is brought by public school teachers in California who argue that their First Amendment rights are violated because they have to pay union dues for speech they don’t support.

Terry Pell, the president of the Center for Individual Rights, a public interest firm representing the teachers, praised the decision by the Supreme Court to take up the case.

“We are seeking the end of compulsory union dues across the nation on the basis of the free speech rights guaranteed by the First Amendment,” Pell said in a statement on Tuesday.

Mandatory union dues are currently forbidden in 25 states, and Pell hopes the Supreme Court will extend that nationwide.

Supporters of the teachers say that the supposed distinction between political spending and collective bargaining is blurred when it comes to public sector unions.

“What the teachers are objecting to is the fact that in the public sector, the distinction between union dues for political activities and union dues for workplace bargaining is artificial,” said Will Collins of the National Right to Work Legal Defense Foundation, a group that has filed a brief in support of the teachers. “All workplace bargaining involving public sector unions necessarily affects the size and scope of government making it an inherently ideological activity.”

But the unions contend the dues for collective bargaining which goes toward issues such as contract negotiations and grievances are not used for political purposes and instead are necessary so that the union can represent all employees whether they are members or not. The unions say they negotiate on behalf of all workers — members or not — and believe that everyone should pay their fair share.

“We are disappointed that at a time when big corporations and the wealthy few are rewriting the rules in their favor, knocking American families and our entire economy off-balance, the Supreme Court has chosen to take a case that threatens the fundamental promise of America: that if you work hard and play by the rules, you should be able to provide for your family and live a decent life,” the four major unions representing public workers said in a statement.