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".
Halsey Frank Halsey Frank is an American attorney. Currently an Assistant United States Attorney in the United States District Court for the District of Maine, he is President Donald Trump's nominee to become U.S. Attorney for the District of Maine. Frank previously served as an Assistant U.S. Attorney in the District of Columbia and as a trial attorney in the torts branch of the civil division in the United States Department of Justice. He has prosecuted a number of high-profile criminal cases in Maine. Frank was recommended for the position of U.S. Attorney by U.S. Senator Susan Collins.