Why did Lochner's lawyers argue that baking did not require special regulation under the police power?

In the case of Lochner v. New York, lawyers for John Lochner argued that the state's maximum-hours law did not fall under the legitimate purview of the police power for several reasons:1

• Nature of the Trade: They contended that baking was a generally healthful occupation, unlike inherently dangerous industries such as mining, and therefore did not require special state regulation.1
• Lack of Health Justification: They argued that the Bakeshop Act was not a genuine health measure but rather an hours regulation disguised with minor sanitation provisions. To support this, they provided an appendix of mortality statistics from England, which suggested that bakers had lower mortality rates than the general population and were comparable to other trades like masons and clerks.1
• Class Legislation: They attacked the law as prohibited class legislation because it applied selectively to certain bakers while excluding others, such as those working in hotels, restaurants, and clubs.1

Ultimately, they warned that if the court permitted this regulation, it would set a precedent where "all trades will eventually be held within the police power," thereby threatening broader economic liberty.1