The difficulty of classifying cases on the police power has not evaporated since the review of decisions for the preceding year. The headings there suggested are used here. Classification on the basis of the objects of the legislation appears too precarious to be attempted with any confidence. It seems safer to work along the line of the subject matters with which the legislation deals. Certain topics are species of a wider genus, and thus the same case may be put in two or more groups. Readers who are dissatisfied with the classification adopted may be assured of the sympathy of the perpetrator.
Thomas R. Powell,
Supreme Court's Construction of the Federal Constitution in 1920-1921,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol20/iss3/1