A union claimed Textron fraudulently hid plans to subcontract work when negotiating a labor agreement, and sued to void the contract. The Supreme Court ruled federal courts cannot hear fraud claims that try to void a contract unless there's an actual breach of the contract itself. For subcontractors, this means you can't use fraud as a reason to escape a signed agreement—courts will dismiss the case before trial.
Fraud claims alone won't void a contract in federal court. You must prove the other party actually broke the contract terms.