It spoofed the whole voting frenzy currently going on.
South Park Elementary had to choose a new mascot for their school. The choices were a giant douchebag or a turd sandwich. Stan didn't think there was a big difference in selecting a giant douche or a turd sanwich, so he decides not to vote. Everyone flips out at his decision. They try to explain the importance of voting in a democracy. During their attempts to get him to vote, Stan realizes that they only want him to vote if he does so for their candidate. P. Diddy and his crew show up at Stan's house and tell him about Puffy's "vote or die" campaign. Stan says he doesn't even know what the hell that slogan means. Puffy tells him it means exactly what it says, vote OR die. Puffy's crew pulls their weapons on him.
Stan is eventually banished from town. He is found in the woods by secluded group of PETA members who have sex with animals. The leader tells him that voting has been the same throughout American history. We have had either a turd sandwich or a giant douche to choose from. Giant douches and turd sandwiches are the only ones willing to kiss enough ass to actually get nominated.
Good stuff.

