In the case of Magenau, Administrator v. Aetna Freight Lines, Inc., 1958, the U.S Supreme Court was tasked with determining whether a Pennsylvania statute that allowed for double damages in wrongful death cases involving motor vehicles violated the Commerce Clause of the Constitution. The plaintiff argued that since interstate trucking companies were subject to this law while operating within Pennsylvania's borders, it unfairly burdened interstate commerce and thus contravened federal authority over such matters as outlined by the Commerce Clause. However, after considering these arguments and reviewing relevant precedents on state power versus federal control under said clause, the court ruled against this contention. It held that states have broad powers to regulate safety on their roads even when it affects interstate commerce unless Congress has specifically legislated otherwise or if such regulations are unreasonable or discriminatory towards out-of-state entities - neither of which was found applicable here.

In the dissenting opinion for Magenau, Administrator v. Aetna Freight Lines, Inc., Justice Frankfurter disagreed with the majority's interpretation of Pennsylvania law and its application to this case. He argued that it was not clear whether Pennsylvania would have allowed recovery in such a situation where an employee died from a heart attack allegedly caused by his employer's negligence. The justice believed that there were insufficient precedents under state law to determine how Pennsylvania courts would rule on this matter. Furthermore, he criticized the majority for making assumptions about state law without adequate evidence or reasoning. In essence, Justice Frankfurter felt that the Supreme Court had overstepped its bounds by interpreting state laws based on their own views rather than deferring to local courts' understanding of those laws.