Whether § 301 of the LMRA preempts only claims formally pleaded as breaches of collective-bargaining agreements, or also state-law claims whose resolution depends on interpreting such agreements.
Holding
Section 301 reaches beyond claims labeled as contract actions and preempts state-law claims that are substantially dependent on analysis of a collective-bargaining agreement.
Reasoning
Section 301 requires a uniform body of federal law to govern suits involving labor contracts. Under Teamsters v. Lucas Flour Co., allowing state law to assign different meanings to collective-bargaining terms would disrupt both the negotiation and administration of those agreements, create uncertainty about the parties' rights, and prolong disputes.
Those concerns do not disappear merely because a plaintiff labels the claim a tort. Questions about what the parties agreed to, including the legal consequences of allegedly deficient performance, must be governed by federal labor-contract law whether they arise in a contract action or a tort action. Otherwise, litigants could evade § 301 simply by recasting contract claims as tort claims.
The Court emphasized a limit on this rule: § 301 does not displace every state law touching employment or a collective-bargaining agreement. State rules that establish nonnegotiable rights and duties independent of a private labor contract may survive. The decisive question is whether the state-law right exists independently of the agreement or instead requires interpreting the agreement's terms.