Members of Congress are considered less trustworthy than used car salespeople. From Gallup:

U.S. Views on Honesty and Ethical Standards in Professions, December 2013

The only profession viewed as worse than Member of Congress is lobbyist, a job dominated by former Members of Congress and their staff.

While this makes for a funny punchline, it is a serious problem. This level of disdain for the people making the most important decisions in the country is not healthy and can become a self-feeding downward spiral. The worse Congress is viewed the less likely good people are going to want to become part of it.