narrowly defeating Congressman James E. Van Zandt by a 51%-49% margin. Clark was appointed to the Democratic Steering Committee in 1963, but conservative Southern Democrats thwarted his efforts to appoint more liberal Senators to committees. He was a critic of the Senate itself, which he called a "self-perpetuating oligarchy" in a 1963 address on the Senate floor. He challenged the seniority system and the filibuster. In 1964, he endorsed Genevieve Blatt, the state Secretary of Internal Affairs, over Judge Michael Musmanno in the Democratic senatorial primary. Clark's opposition to Musmanno was not well received by the Italian American community, who largely voted against Clark in 1968. A member of the Senate Foreign Relations Committee, he voted for the Gulf of Tonkin Resolution in 1964 but soon became an outspoken opponent of the Vietnam War, condemning the war's escalation in 1965. In 1968, Clark was defeated for re-election to a third term by Congressman Richard Schweiker, losing 52% to 46%. His defeat is generally ascribed to his support of gun control, especially the 1968 Gun Control Act, and opposition to the Vietnam War. His campaign chairman in 1968 was Bucks County author James A. Michener. Later life and death Following his departure from the Senate, Clark served as a professor at Temple University in 1969. He was president of World Federalists U.S.A., an organization promoting the creation of a world government, from 1969 to 1971. He also served as chairman of the Coalition on National Priorities and Military Policy, and continued to attend meetings of Members of Congress for Peace Through Law. A strong opponent of Mayor Frank Rizzo, he supported Bill Green III in the 1971 Democratic primary and then Republican W. Thacher Longstreth in the general election. He was chairman of independent candidate Charles Bowser's campaign in 1975. He was an elected member of both the American Academy of Arts and Sciences and the American Philosophical Society. Clark died at his home in Chestnut Hill, at age 88. His remains were cremated and interred at St. Thomas' Church Cemetery in Whitemarsh, Pennsylvania. Personal life and family Joseph Clark was descended from a prominent financial family in Philadelphia. His great-grandfather, Enoch White Clark, was the founder of E. W. Clark & Co. Enoch's son Edward was Clark's paternal grandfather and brother of Clarence Howard Clark Sr. Clarence Sr.'s son Clarence Jr. served as president of the Centennial National Bank. Clark