From Contact Music:
"And while bosses of the show have yet to confirm the plans, Alda and Smits are very enthusiastic about it.
Alda says, "I love that sense of danger. The only training I had as an actor was as an improviser. It kind of fits with my aspiration to be as spontaneous as I can be.
"In fact, when I was a young man on the stage, if another actor missed an entrance and I was alone on stage, I thought, 'Oh boy, is this great? I can make up my own play now!'
"So the opportunity to do a presidential debate, although it's scripted, it'll be live, and there'll be a certain amount of uncertainty - my blood is up for that."
The article says the episode will air on November 5. However, this is a Saturday so it is not clear whether the information is correct.
From the San Bernardino Sun:
" A live debate with the leads planted at podiums and at least a portion of the script on TelePrompTers could actually be an easy production compared with a regular "West Wing" episode. Its scripts often include several long tracking shots through corridors and stairwells with dialogue for several actors.
The production team for "The West Wing" would be able to draw on the institutional memory of the highly rated 1997 "ER" live episode, which also was produced by John Wells for Warner Bros. Television. The scenario for "ER" had a documentary crew shooting in the hospital emergency room; the day-in-the-life story was shown through the perspective of their multiple cameras. The "ER" episode was performed twice for East and West Coast time periods, so it is likely "The West Wing" would do the same."