Next week’s annual conference for Minnesota teachers will be shorter than in previous years, and open only to members of Education Minnesota, the state teachers’ union.

The Minnesota Educator Academy, or MEA, has traditionally been held for two days in mid-October — a time during which many Minnesota schools are closed and families with school-age children often cause a surge in airport traffic as they head out on short vacations.

But this year, leaders of Education Minnesota, which puts on the conference, say they are scaling back the event in response to a recent decision by the U.S. Supreme Court.

In June, the court ruled that public employees who do not join unions cannot be required to pay for collective bargaining. Union leaders said in a news release Monday that the decision and the “national, billionaire-funded, anti-union campaign that followed it” pushed them to make the change.

“The MEA conference will still be there for all our members who need training for re-licensure or who want to improve their skills,” said Denise Specht, Education Minnesota’s president. “But in this new environment, union educators can no longer subsidize the professional development that should be provided by the charter-school industry and private schools.”

It’s not yet clear what kind of an impact the court’s ruling has had on the union, which had about 90,000 members before the decision was released. Education Minnesota’s annual, one-week window in which teachers can opt out of membership closed at the end of September, but Specht has said the union does not plan to disclose its updated membership numbers.

This year’s MEA conference will be held Oct. 18 at the St. Paul RiverCentre and will feature speakers on the topics of mental health, the effects of social media on young people and “community organizing for strong public schools.” The union said classes on student mental health, suicide prevention, cultural competency and increasing student engagement have been yielding significant interest from teachers who have already registered for conference sessions.

Education Minnesota spokesman Chris Williams said organizers expect between 2,000 and 2,500 people will attend the event.

Despite the shorter conference, many school districts still won’t hold classes on Oct. 18 and 19.