Federal executive branch Matt Santos (Jimmy Smits): Democratic candidate for president in 2006 (Seasons 6–7). Succeeds Josiah Bartlet as President of the United States. (Season 7). Three-term U.S. Representative from Texas. Frustrated at legislative setbacks in the House, Santos is on the verge of announcing a decision not to seek re-election, but instead is convinced by Josh Lyman to launch a long-shot campaign for the presidency. John Hoynes (Tim Matheson): President Bartlet's first Vice President. President Bartlet's rival for the 1998 Democratic presidential nomination. Resigned from office while under fire for leaking classified material to a woman he was having an affair with. Candidate for the Democratic nomination for the 2006 election. (Seasons 1–4 and appearances in Season 5, 6 and 7) Robert "Bob" Russell (Gary Cole): President Bartlet's vice president after the resignation of John Hoynes and a candidate for the Democratic nomination for the 2006 election. (Seasons 5–7) Lewis Berryhill (William Devane): Secretary of State. Was nearly nominated by President Bartlet for the office of vice president after John Hoynes' resignation. (Seasons 4–7) Miles Hutchinson (Steve Ryan): Secretary of Defense. Often disagreed, loudly and at length, with the policy decisions of President Bartlet. (Seasons 4–7) Federal legislative branch Senator Seth Gillette (Ed Begley, Jr.): Democrat from North Dakota. Threatened to run against President Bartlet as a third-party candidate on a more left-wing platform in the 2002 election. (Ep 2.14) Rep. Jeff Haffley (Steven Culp): Republican from Washington; House Majority Whip, 1997–2003, Speaker of the House, 2003–2007 Senator Howard Stackhouse (George Coe) Democrat from Minnesota. Ran a liberal third-party candidacy for the Presidency in 2002 but later endorsed President Bartlet. (Ep 2–17, 4.04, 4–06) Senator Arnold Vinick (Alan Alda): Republican from California. Republican candidate for president in 2006 (Seasons 6–7). Nominee for Secretary of State in Santos Administration (Season 7). Senator from 1983 to 2007, was California's senior US Senator in 2006. Chairman of a powerful Senate Committee (either Judiciary or Finance), and also served on the Foreign Relations and Environment Committees Rep. Glen Allen Walken (John Goodman): Republican from Missouri; House Majority Whip, 1995–1997; House Majority Leader, 1997–2001; Speaker of the House, 2001–2003. Became Acting President of the United States when President Bartlet temporarily relinquished power. Later a contender for the Republican presidential nomination in the 2006 election, though he never appeared on screen in that capacity. State governors Eric Baker (Ed O'Neill): Governor of Pennsylvania. Widely tipped