For thousands of state and municipal employees, this coming June will mark more than the end of the legislative session. It will also likely bring a decision in a closely watched U.S. Supreme Court case that could forever change the face of public employee unions in New York and nationwide.

If the justices rule on behalf of the union in Friedrichs vs. California Teachers Association, there should be no changes in the mandatory dues provisions that exist in about half the nation’s states including New York that compel public sector union members to pay their dues.

If they rule for the plaintiff, though, the practice of collecting mandatory dues, known as agency fees, would end. Unions would have to convince their members that dues, which can run hundreds of dollars per year, are worthwhile since they fund activities used in collective bargaining.

The case is being watched particularly closely in the Capital Region where there is a high concentration of unionized state workers.

Response to the case from union leaders has ranged from ringing the metaphorical alarm bell to expressing confidence that their dues-paying membership will hold together without mandatory payments.

But most are planning at least some kind of membership outreach if the justices on the court rule against the union.

“With the threat of the Friedrichs case looming since I took office six months ago, my team took immediate steps to head off an adverse decision in the case. We immediately started a campaign to reach each and every one of our fee payers to show them the benefits of being a part of PEF,” Public Employees Federation President Wayne Spence said in a prepared statement.

“Just as importantly, we used this case as an opportunity for a larger member engagement plan that includes town hall meetings and has focused on showing our members the history, benefits and protections being in a union provides.”

Agency fee payers are people represented by a particular union who don’t actually belong to the organization, for whatever reason.

But in about half the states including New York they must pay so-called agency fees, which are the portion of their dues that go toward the union’s work on bargaining and other issues.

They can get a rebate on a smaller part that goes toward political activity.

It was the agency fee provision that prompted suburban Los Angeles teacher Rebecca Friedrichs to sue her state teachers union.

Friedrichs has said in interviews that she objects to the tenure rules enforced by her union, that has allowed incompetent teachers to remain on the job, as well as other stances by the union with which she disagrees.

So with the backing of several conservative groups, she sued to overturn the agency fee provision.

Her lawyers argued that it violates the First Amendment, since it compels her to participate in a political activity — a form of free speech.

While the agency fees are described as separate from the political part of her dues, Friedrichs’ lawyers argued that all union activities are inherently political since they involve the spending of public tax dollars.

(That helps explain why the case focuses only on public sector unions. Non-public sector unions bargain with private employers, not the government).

A look at federal data shows that, among some New York public sector unions, agency fee payers are a small minority, suggesting there is little active animosity toward dues or the unions.

Agency fee payers range from about 3 percent of membership (NYSUT) to 6 percent (Civil Service Employees Association) or 5 percent (PEF).

The fear, however, is that, with the option of paying nothing, dues paying members could drift away.

With less money for organizing and lobbying in the Legislature — a public sector union stronghold — unions could eventually find themselves at a heretofore unknown disadvantage.

Much of New York’s public sector union strength comes from laws passed by the Legislature, such as provisions that workplace conditions including longevity raises remain in place, even if a contract has expired.

It’s unclear how the Supreme Court will rule but conservatives hold a 5-4 majority and the Court is said to have been wanting to hear such a case for some time.

“If I had to guess I’d say that they will have a 5-4 decision saying it is an infringement on freedom of speech,” predicted Mike Billok, a lawyer with Bond Schoeneck & King which represents employers.

A broad ruling, such as one that says agency fees can’t be automatically deducted, could mean that members would have to affirmatively “opt in” to paying their dues.

“If the court rules for the plaintiff and early indicators are that it will, the impact will be pretty monumental,” saidKen Girardin, spokesman for the Empire Center, a fiscally conservative think tank.

The Empire Center calculated that the state’s five largest public sector unions, NYSUT, CSEA, PEF, the New York City-based Transport Workers and District Council 37 municipal workers unions, collected $338 million in dues from their combined 797,954 members in 2014.

Individual dues vary, they found.

A $50,000-a-year CSEA worker pays $605 annually while a Buffalo teacher and NYSUT member pays a total of $917.

History suggests that at least some members stop paying their dues for some time if the automatic deductions are halted.

When TWU members walked off the job in a 2005 transit strike, a judge suspended their dues check-offs.

A year later, after the strike was resolved, only about half the members had been paying the dues, the Empire Center found.

Some union officials, though, believe they can make the case for dues even if they aren’t mandatory.

“We are confident that NYSUT members see the value in union membership and that they understand the importance of having a voice in their own school districts and the corridors of Albany,” said NYSUT spokesmanCarl Korn.

“As difficult as the educational environment has been in the last two years, NYSUT members recognize it’s essential to have a strong voice.”

The union won a major victory in recent months when Gov. Andrew Cuomo as well as the state Board of Regents halted what had been a controversial system of test-based teacher evaluations.

Parents had complained of over-testing and teachers said the tests were flawed, but the union’s well-organized and amply financed pushback against the evaluation system may have tipped the scales in the Capitol where interest group politics carry a lot of weight.

CSEA spokesman Stephen Madarasz pointed out that his union has been doing more outreach, even before the Friedrichs case arose, as a response to the nation’s growing gap between rich and poor and a shrinking middle class. Public sector unions for years have argued that they are one of the bastions of middle class America, and they’ll be amplifying that message as time goes on.

“Our members appreciate being part of a statewide organization and a Labor Movement that’s bigger than themselves but they need to feel the connection more strongly as individuals where they work and live,” Madarasz said in a prepared statement.

He explained in a phone interview that they are reaching out to their numerous local affiliates — CSEA represents both state and municipal workers — and getting input from members about what is important to them, That effort, he added, began before the Friedrichs case arose.

“At the end of the day a union only works when people support it,” said Madarasz.

© 2016 Times Union