I was going to post about 2005, so let me add some specifics:
Congress failed to move on W's big legislative items that he ran on in 2004, especially his proposals for Social Security.
App and May were terrible months in Iraq, and thoughts of a withdrawal were abandoned, disappointing the public.
Hurricane Katrina put government failures nightly on TV.g
Majority Leader Tom DeLay was indicted and resigned.
Jack Abramoff was indicted in a lobbying scandal touching the Administration and Congressional Pubs.
Cong. Duke Cunningham resigned as part of his scandal involving defense contracts.
These set the stage for the Pub collapse in the 2006 midterms.