User: Can you give me some background on Perez v. Campbell
Assistant: Perez v. Campbell, 402 U.S. 637 (1971), was a case in which the Supreme Court of the United States held that Arizona's law suspending a driver's license was unconstitutional due to its conflict with the federal Bankruptcy Act under the Supremacy Clause of the Constitution.

The plaintiffs, Mr. Adolfo and Mrs. Emma Perez, were licensed uninsured motorists in the state of Arizona. Insurance was not required under Arizona law. Mr. Perez was involved in a traffic accident and, unable to pay the associated costs, soon filed for bankruptcy. Arizona, under its financial responsibility laws, withdrew the Perez' licenses, and the couple filed suit in district court, where their claim was denied. The Perez family's appeal to the United States Court of Appeals for the Ninth Circuit was denied, and they subsequently appealed to the United States Supreme Court, which granted certiorari.