A quick visit to the show's main site says tomorrow's episode is entitled "Obama Wins!"
Here's the press release of the episode description:
"NEW YORK, November 5, 2012 - The presidental election isn't over until you watch this all-new episode of "South Park" titled "Obama Wins!" premiering Wednesday, November 7 at 10:00 p.m. ET/PT on Comedy Central.
Cartman is hiding something in his bedroom that could change the outcome of the entire election. While Americans innocently plan to go to sleep Tuesday night with the election results counted and a winner announced, Cartman has secretly wrestled control of the presidential election from the voters."