The Supreme Court announced Tuesday that it will not decide whether a type of agreement between employers and unions that has become increasingly important to the labor movement violates the law.

The court dismissed as “improvidently granted” a case it heard last month that both unions and right-to-work groups had called one of the major labor issues of the term. The terminology means that justices found a procedural flaw in the case that kept them from deciding it.
If the case is moot, he said, the court should likely vacate the 11th Circuit’s decision.

“Unless resolved, the differences among the courts of appeals could negatively affect the collective-bargaining process,” Breyer wrote.
Supreme Court drops case on employer-union ‘neutrality agreements’ - The Washington Post