In the 1944 case of State Farm Mutual Automobile Insurance Co. v. Duel, Commissioner of Insurance, the U.S Supreme Court ruled in favor of State Farm. The insurance company had challenged a California law that required out-of-state insurers to maintain substantial assets within the state as a condition for doing business there. The court found this requirement unconstitutional because it violated both due process and equal protection clauses by discriminating against foreign corporations without any reasonable basis or relation to public policy objectives such as protecting policyholders from insolvency risks. This decision reinforced principles of economic liberty and interstate commerce by limiting states' ability to impose burdensome conditions on businesses seeking access to their markets.

In the dissenting opinion for State Farm Mutual Automobile Insurance Co. v. Duel, Commissioner of Insurance (1944), it was argued that the majority's decision to uphold California's statute requiring out-of-state insurance companies to maintain a certain amount of assets in state as a condition for doing business there violated the Commerce Clause of the U.S. Constitution. The dissenters contended that this requirement placed an undue burden on interstate commerce by effectively forcing non-California insurers to establish and maintain substantial operations within California, even if their primary business activities were conducted elsewhere. They also disagreed with the majority's interpretation of previous case law regarding states' rights to regulate insurance businesses within their borders, arguing instead that these cases supported a more limited role for state regulation in light of federal supremacy over interstate commerce matters.