Illustration of the United States Capitol with a broom in front of it with red text above and bleow and three thin outer red rings on a white background
This button comes from the 1970s or 1980s. "Clean up Congress" refers to a campaign to replace incumbents with new Congressmen and Senators who promise to listen to their constituents needs better than their predecessors have. It also often involves a call for term limits so that the same people cannot stay in Congress forever. The argument is that membership in Congress corrupts and Congressmen think more about their reelection than policy. Advocates also argue that campaign finance laws make it too easy for incumbents to get reelected year after year and too hard for anyone to successfully challenge them. In the 1980s advocates for cleaning up Congress were often aligned with the Republican Party.
Sources: Williams, B. (1989, August 30). Clean up Congress. Moscow-Pullman Daily News.