From NBC : "In a first for NBC's 'The West Wing' (Sundays, 8-9 p.m. ET), the Emmy Award-winning series will broadcast a live episode featuring a debate between presidential candidates Congressman Matt Santos (Jimmy Smits) and Senator Arnold Vinick (Alan Alda) on Sunday, Nov. 6 (8-9 p.m. ET).
Very few contemporary drama series have attempted live episodes. NBC's 'ER' -- also from executive producer John Wells -- produced a live episode for its fourth season premiere in September 1997.
The format of the episode will allow for a tension-packed debate between Democrat Santos and his Republican opponent Vinick. Two live versions will be telecast, one for the East Coast and another for the West Coast. This episode will be written by Lawrence O'Donnell, and directed by Alex Graves, both executive producers of the series. "