Even before it was announced, the U.S. Supreme Court’s long-anticipated decision in Janus v. AFSCME triggered responses from public-sector unions in Hawaii and nationwide.

They knew what was coming.

The conservative majority on the court, citing the First Amendment, on Wednesday ruled 5-4 that nonunion workers cannot be forced to pay so-called service or agency fees to public-sector unions. Those fees, the court found, could be used to help conduct political advocacy objectionable to the worker.

Union advocates blasted the ruling as an all-out effort to weaken and eventually get rid of public worker unions, long the goal of conservative organizations. This is not a far-fetched claim. Well-funded conservative groups already have begun campaigns to convince workers to stop paying the fees.

Local unions have responded to Janus appropriately by more closely managing their budgets and reaching out to their members to stress the value of collective bargaining.

The Hawaii Government Employees Association (HGEA), the state’s largest public employee union, stopped collecting the service fees on Wednesday, but has been urging its members to stay the course.

“We’re going to continue to be advocates for the people we represent, and hope and trust that people see the value in the union and continue to be members,” said Randy Perreira, executive director of the 42,000-strong organization.

Whether public unions can survive and thrive post-Janus should be an issue of heightened public concern in our state.

Hawaii’s union history, dating back to plantation days, is woven into the historical and cultural fabric of the islands. The right of public workers to organize is enshrined in the state Constitution and in statute, and unions enjoy broad support in Democratic Party-dominated Hawaii.

Overall, union membership rates in the islands are the second-highest in the country; in 2017, 22.9 percent of Hawaii workers are represented by a union, according to the U.S. Bureau of Labor Statistics. That’s an increase of 2 percentage points from the previous year.

Hawaii’s government unions represent some of our most critical human resources: teachers, firefighters, police officers, prison guards, university faculty and many other civil servants.

Over the long term, public workers could face an uncertain economic future if more of them opt out of paying dues, causing their representation to grow weak and ineffective.

That’s a problem, says U.S. Sen. Brian Schatz, because unions “have served as a strong counterweight to economic inequality” and “support the middle class.”

Public sector unions traditionally have been supporters of Democratic Party politics, and party stalwarts have taken note.

U.S. Sen. Mazie Hirono and U.S. Rep. Matt Cartwright announced plans to introduce the Public Service Freedom to Negotiate Act, “to ensure that public sector employees across the country are able to form and join a union and enter into a written contract with employers.”

Hawaii’s Legislature, anticipating major GOP-supported policy changes coming out of Washington, passed House Bill 1932, which would allow the state to pass emergency, temporary rules “to meet the requirements of federal law” while “preserving the values and goals of Hawaii law.”

However, it seems unlikely these efforts will amount to much if public employee unions can’t get its members to buy in.

Hawaii’s high cost of living will make it tempting for employees to keep their money. And as Star-Advertiser columnist Richard Borreca notes in today’s column, political engagement is down and millennials aren’t thinking about settling into the life of a bureaucrat with an iffy pension plan.

Furthermore, the unions should be more concerned about the financial health of their employer — that’s us, the taxpayers. That outlook is uncertain at best. The state’s unfunded liability for its public pension and health-care benefits now top $25 billion, raising doubts that those millennials will even see a pension. Benefits for new employees have been reduced, and it’s getting more difficult to fill vacancies with long-term, loyal union workers.

It seems self-evident that for public-sector unions in Hawaii to continue to thrive on voluntary contributions, they will have to adapt. That could mean offering different services its younger members want. But it also could mean negotiating contracts that allow for more flexible working conditions, rewarding innovation and allowing employees and management to move more nimbly to meet rapidly changing technological and societal norms. It should mean unions that are full partners in helping government operate as efficiently and effectively as possible, advocating good public policy as well as good wages and benefits.

Such an approach has worked elsewhere. Unionized teachers and other workers in right-to-work states — where dues are not required — found unity and strength under the common banner of helping not only themselves, but the communities they serve.

In similar ways, Hawaii’s public employee unions have thrived and can continue to do so, even after Janus.