Across the state, teachers’ unions are trying to negotiate pay increases for their members. At the same time, a conservative group is telling teachers they can get that extra compensation without paying any union dues.

Teachers in the Puget Sound region have received mailings recently from the Olympia-based Freedom Foundation telling them they don’t have to financially support a union.

“Most of the people that I’ve talked to have kind of laughed about it,” said Grant Ruby, a high school math teacher in Tacoma and part of the Tacoma Education Association’s executive board.

The U.S. Supreme Court ruled last month in Janus v. AFSCME Council 31 that public employees who choose not to become full members of a union do not have to pay what’s known as “agency fees” to cover the cost of collective bargaining. The court’s majority said requiring public-sector workers to financially support a union they disagree with is a violation of their free-speech rights.

The Freedom Foundation is a conservative group that says public-sector unions are too cozy with government. It doesn’t disclose who its funders are, but tax filings show the group has gotten financial support indirectly from wealthy conservatives such as Charles Koch.

Labor groups say the organization just wants to weaken them and undermine policies that protect workers.

Since the court decision, the Tacoma Education Association has not felt a big impact, Ruby said.

“So far we haven’t seen a lot of membership drop, but it’s summertime and we’ll see how that changes as fall approaches,” he said.

In the long term, Ruby said he’s “gravely concerned” about the effects of the decision on public-sector unions because membership has dropped in states such as Wisconsin after they enacted right-to-work laws.

Groups such as the Freedom Foundation have been gearing up for the Janus decision for years.

Maxford Nelsen, director of labor policy for the Freedom Foundation, said his organization has been collecting public-sector employee names through public records requests for about two years. And while his group didn’t receive home addresses for employees through those requests, he said addresses are readily available.

“We cross-reference the list we receive from the state or a public employer with the state voter registration database and if somebody’s a match, then we send to their address there,” he said. “Because all voters’ mailing addresses are published in the voter file.”

Nelson said the Freedom Foundation has sent out about 180,000 fliers to teachers and other public employees to tell them about the court decision. He said the group plans additional mailings in the future.