In the case of Walsh, DBA Tom Walsh & Co. v. Schlecht et al., Trustees (1976), the U.S. Supreme Court ruled on a dispute involving labor agreements and arbitration clauses in contracts between construction contractors and unions representing their employees. The court held that an agreement to arbitrate disputes over interpretation or application of a collective bargaining contract must be enforced under federal law, even if state law would otherwise invalidate such an agreement as contrary to public policy or for other reasons. The decision was based on Section 301(a) of the Labor Management Relations Act which allows parties to sue in federal court for breaches of collective bargaining agreements, but also requires courts to respect terms agreed upon by both sides including any provisions requiring arbitration before litigation can proceed. This ruling clarified that when it comes to enforcing labor contracts with mandatory arbitration clauses, federal law preempts conflicting state laws - reinforcing the principle that national interests in maintaining industrial peace through effective mechanisms for resolving labor disputes take precedence over individual states' policies.

In the dissenting opinion for Walsh, DBA Tom Walsh & Co. v. Schlecht et al., Trustees, Justice Brennan disagreed with the majority's interpretation of Section 302(c)(5) of the Labor Management Relations Act (LMRA). He argued that it was not Congress' intention to allow trust funds to collect delinquent contributions from employers based on hours worked by employees under collective bargaining agreements in other states where such agreements did not specifically provide for such payments. According to him, this would result in an unjust enrichment of these trust funds at the expense of employers who had no say in their establishment or operation and could potentially lead to double liability for these employers if they were also required to contribute towards similar local trusts. Furthermore, he contended that allowing trustees broad powers over interstate commerce without any checks or balances violated principles of federalism and state sovereignty.