When Homer disposes of a leaky battery along with his fast food containers, he causes an explosion that destroys Springfield's fast-food district. Mayor Quimby proposes to rebuild the district during the next election. The next election, however, isn't until June, so Quimby decides to move it to the upcoming Saturday. This change makes Springfield the first city in the nation to hold a presidential primary. Excitement builds as reporters from around the country descend upon Springfield to cover the debate. The news is dismal though as the candidates turn out to be less than compelling. On the night of the primary, Kent Brockman announces an unexpected turn of events: Springfield voters rejected all the leading candidates and embraced a write-in: Ralph Wiggum. Much to Lisa's chagrin, the leaders of both parties realize that embracing Ralph as a candidate means certain victory come November. Although no one knows for sure which political party Ralph is representing, he insists that everyone is invited to his party.