William Hubbs Rehnquist (October 1, 1924 – September 3, 2005) was an American lawyer, jurist, and political figure who served as an Associate Justice of the Supreme Court of the United States and later as the 16th Chief Justice of the United States. Considered a conservative, Rehnquist favored a conception of federalism that emphasized the Tenth Amendment's reservation of powers to the states. Under this view of federalism, the Supreme Court of the United States, for the first time since the 1930s, struck down an Act of Congress as exceeding its power under the Commerce Clause.