Famously liberal actor Alan Alda (who’s appearing here on Sunday, November 20), rejuvenated his career by taking on the role of Republican presidential candidate Sen. Arnold Vinick on The West Wing.

Last week, The West Wing experimented with a fictional debate between Vinick and Democratic candidate Rep. Matt Santos (Jimmy Smits). The debate was minimally scripted: Both Alda and Smits ad-libbed for the entire hour on the Iraq war, Social Security reform, free markets and intelligent design in public schools. To cap things off, NBC hired pollers Zogby International to survey viewers.

In a recap of the episode in the Washington Post [BugMeNot], Lisa de Moraes notes that Alda’s candidate was the clear winner among younger viewers:

Before the episode, viewers between 18 and 29 preferred Santos over Vinick, 54 percent to 37 percent. But after the debate, in which veteran Alda gutted pretty-boy Smits without him even knowing it, Vinick now leads among viewers under age 30, 56 percent to 42 percent.