“The Lochner line of cases pioneered the protection of the right of women to compete with men for employment free from sex-based regulations, the right of African Americans to exercise liberty and property rights free from Jim Crow legislation, and civil liberties against the states ranging from freedom of expression to the right to choose a private school education for one’s children.”
Rather than being lumped together with the Plessy case, Bernstein argues, the Lochner ruling should be regarded as the anti-Plessy—a decision that refused to defer to stereotypes and self-dealing among the ruling class.
It is important to note that Lochner wasn't about just working conditions so much as an effort by large, politically connected groups to force out their small competitors:
As is often the case with regulation, large bakeries didn’t mind the law governing maximum hours because they could hire multiple shifts. Small bakeries, with their smaller workforces, found compliance far more difficult. Small bakers felt that the law was enforced much more vigorously where nonunion bakeries were concerned, and Lochner, an immigrant who had opened his own bakery in Utica in 1894 where he worked alongside his wife and employees, soon attracted official attention.
Elsewhere, as Bernstein recounts, advocates for African-Americans’ and women’s rights often made use of freedom of contract as a way to strike down laws limiting those groups’ economic freedom. Freedom of contract was a powerful weapon for dissolving the legal rules that, unsurprisingly, tended to work against those excluded from legislative power. Economic freedom, far from being a tool of the big bosses, was an important way for the underdogs to gain the freedom to compete, and to undermine the legal support that was essential to making Jim Crow and related laws work.