The Court, in an opinion by Chief Justice Hughes, ruled that the Constitution permitted the restriction of liberty of contract by state law where such restriction protected the community, health and safety, or vulnerable groups, as in the case of Muller v. Oregon,[2] where the Court had found in favor of the regulation of women's working hours.

More than twenty-five years ago we set forth the applicable principle in these words, after referring to the cases where the liberty guaranteed by the Fourteenth Amendment had been broadly described.

The guaranty of liberty does not withdraw from legislative supervision that wide department of activity which consists of the making of contracts, or deny to government the power to provide restrictive safeguards.

Those principles have been reenforced by our subsequent decisions.The West Coast decision heralded the end of the Lochner era, when the US Supreme Court struck down numerous worker and consumer protection laws.

During the Lochner era, the Supreme Court's conservative majority held that the Fourteenth Amendment guaranteed a "freedom of contract," which trumped efforts by legislators to protect workers or consumers.

The doctrine continued to inform the Court's decisions through the Great Depression and the beginning of the New Deal, when it invalidated numerous worker and consumer protections.

[7][8] In one of his notes from 1936, Hughes wrote that Roosevelt's re-election forced the court to depart from "its fortress in public opinion" and severely weakened its capability to base its rulings on personal or political beliefs.

[7] Roberts had voted in favor of Washington State's minimum wage on December 19, 1936,[6] just two days after oral arguments concluded,[9] and the Court was evenly divided only because pro-New Deal Associate Justice Stone was then absent for illness.

Roberts prepared a short memorandum that discussed his alleged change of stance around the time of the court-packing effort, which he left in the hands of Justice Felix Frankfurter.

[10] In his dissenting opinion, Associate Justice Sutherland wrote that "the meaning of the Constitution does not change with the ebb and flow of economic events,"[11] a remark that has been read as an admonition aimed at Roberts.