I know of many of hard core liberals who consider the ADA itself flawed. They complain that the ADA rating is itself setup to give centrist and moderate Democrats high ratings. If that is true, using it as a general rating the way this survey does would produce a democratic leaning tilt.

More over, assuming the Congress reflects the public at large is a mistake. Previous studies have shown that Congress is more conservative then the public at large. Generally just a bit, but Congress is notable more free market then the public at large.

Jay