Fourteenth Amendment, Section 1:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
As noted, even during the Lochner era, the Due Process Clause was construed as permitting enactment by the states of maximum hours laws applicable to women workers 1 and to all workers in specified lines of work thought to be physically demanding or otherwise worthy of special protection. 2 Similarly, the regulation of how wages were to be paid was allowed, including the form of payment, 3 its frequency, 4 and how such payment was to be calculated. 5 And, because of the almost plenary powers of the state and its municipal subdivisions to determine the conditions for work on public projects, statutes limiting the hours of labor on public works were also upheld at a relatively early date. 6 Further, states could prohibit the employment of persons under 16 years of age in dangerous occupations and require employers to ascertain whether their employees were in fact below that age. 7
The regulation of mines represented a further exception to the Lochner era’s anti-discrimination tally. As such health and safety regulation was clearly within a state’s police power, a state’s laws providing for mining inspectors (paid for by mine owners), 8 licensing mine managers and mine examiners, and imposing liability upon mine owners for failure to furnish a reasonably safe place for workmen, were upheld during this period. 9 Other similar regulations that were sustained included laws requiring that underground passageways meet or exceed a minimum width, 10 that boundary pillars be installed between adjoining coal properties as a protection against flood in case of abandonment, 11 and that wash houses be provided for employees. 12
One of the more significant negative holdings of the Lochner era was that states could not regulate how much wages were to be paid to employees. 13 As with the other working condition and wage issues, however, concern for the welfare of women and children seemed to weigh heavily on the justices, and restrictions on minimum wages for these groups were discarded in 1937. 14 Ultimately, the reasoning of these cases was extended to more broadly based minimum wage laws, as the Court began to offer significant deference to the states to enact economic and social legislation benefitting labor.
The modern theory regarding substantive due process and wage regulation was explained by Justice Douglas in 1952 in the following terms:
Our recent decisions make plain that we do not sit as a super-legislature to weigh the wisdom of legislation nor to decide whether the policy which it expresses offends the public welfare. The legislative power has limits. . . . But the state legislatures have constitutional authority to experiment with new techniques; they are entitled to their own standard of the public welfare; they may within extremely broad limits control practices in the business-labor field, so long as specific constitutional prohibitions are not violated and so long as conflicts with valid and controlling federal laws are avoided. 15
The Justice further noted that
many forms of regulation reduce the net return of the enterprise. . . . Most regulations of business necessarily impose financial burdens on the enterprise for which no compensation is paid. Those are part of the costs of our civilization. Extreme cases are conjured up where an employer is required to pay wages for a period that has no relation to the legitimate end. Those cases can await decision as and when they arise. The present law has no such infirmity. It is designed to eliminate any penalty for exercising the right of suffrage and to remove a practical obstacle to getting out the vote. The public welfare is a broad and inclusive concept. The moral, social, economic, and physical well-being of the community is one part of it; the political well-being, another. The police power which is adequate to fix the financial burden for one is adequate for the other. The judgment of the legislature that time out for voting should cost the employee nothing may be a debatable one. It is indeed conceded by the opposition to be such. But if our recent cases mean anything, they leave debatable issues as respects business, economic, and social affairs to legislative decision. We could strike down this law only if we returned to the philosophy of the Lochner, Coppage, and Adkins cases. 16