It's a slow beginning, but Stewart is using this story to make a point that he and Colbert raised after the Supreme Court's Citizens United ruling. Back then, they created a real super pac to demonstrate how manufactured the election process has become and how the "red vs blue" polarized media narrative is a red herring that fuels the corporatization of American politics at the expense of the American people.
SPOILER: the twist at the end of the film suggests how regular citizens might cleverly come together to take back control and fund public projects that benefit communities. Be sure to watch through the credits for the interview with the former head of the Federal Election Commission. It's a little on-the-nose, but he's making important points that, regardless of political beliefs, we should all be aware of.