29 U.S.C. § 164 — Construction of provisions

(a) Supervisors as union members Nothing in this law stops an individual who works as a supervisor from becoming or staying a member of a labor organization. But no employer covered by this subchapter has to treat supervisors, as this section defines them, as "employees" for purposes of any collective-bargaining law, whether national or local. (b) Agreements requiring union membership in violation of State law This subchapter does not authorize enforcing an agreement that requires union membership as a condition of employment, in any state or territory where state or territorial law bans that kind of agreement. (c) Power of Board to decline jurisdiction of labor disputes; assertion of jurisdiction by State and Territorial courts (1) The Board may, at its discretion, by rule of decision or by published rule adopted under subchapter II of chapter 5 of title 5, decline to hear a labor dispute involving a class or category of employers — if, in the Board's opinion, the dispute's effect on commerce is not substantial enough to justify using its power. But the Board cannot decline to hear a labor dispute that it would have accepted under the standards that applied on August 1, 1959. (2) This subchapter does not stop any state or territorial agency or court — including in Puerto Rico, Guam, and the Virgin Islands — from taking up and deciding labor disputes that the Board declines to hear under paragraph (1).