Three separate lists of Supreme Court decisions appear below: part I lists cases holding state constitutional or statutory provisions unconstitutional, part II lists cases holding local laws unconstitutional, and part III lists cases holding that state or local laws are preempted by federal law. As Congress acted as the legislature for the District of Columbia until passage of the Home Rule Act on December 24, 1973, District of Columbia statutes that were enacted by Congress are treated as federal statutes (and included in a prior appendix), and District of Columbia statutes enacted by the District of Columbia government are treated as state statutes. Each case is briefly summarized, and the votes of Justices are indicated unless the Court’s decision was unanimous. Justices who write or join the majority or plurality opinion are listed under “Justices concurring”, whether or not they write separate concurring opinions, and Justices who do not join the majority or plurality opinion, but write separate opinions concurring in the result, are listed under “Justices specially concurring.” Previous editions contained only two lists, one for cases holding state laws unconstitutional or preempted by federal law, and one for unconstitutional or preempted local laws. The 2002 edition added the third category because of the different nature of preemption cases. State or local laws held to be preempted by federal law are void not because they contravene any provision of the Constitution, but rather because they conflict with a federal statute or treaty, and through operation of the Supremacy Clause. Preemption cases formerly listed in one of the first two categories have been moved to the third. A few cases with multiple holdings are listed in more than one category.
