Evan L. Schwab  served as law clerk to a US Supreme Court Justice that was nominated by which president?
William O. Douglas William Orville Douglas (October 16, 1898January 19, 1980) was an American jurist and politician who served as an Associate Justice of the Supreme Court of the United States. Nominated by President Franklin D. Roosevelt, Douglas was confirmed at the age of 40, one of the youngest justices appointed to the court. His term, lasting 36 years and 211 days (1939–75), is the longest in the history of the Supreme Court. In 1975 "Time" magazine called Douglas "the most doctrinaire and committed civil libertarian ever to sit on the court".
William Rehnquist William Hubbs Rehnquist (October 1, 1924 – September 3, 2005) was an American lawyer and jurist who served on the Supreme Court of the United States for 33 years, first as an Associate Justice from 1972 to 1986, and then as the 16th Chief Justice of the United States from 1986 until his death in 2005. 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 court, for the first time since the 1930s, struck down an act of Congress as exceeding its power under the Commerce Clause.