Could you be thinking of Congressman Dan Rostenkowski from Chicago? I remember a clip (from the late 80's, I think) of some oldsters pounding on his car as it was pulling away. Funny as hell!
No, the event I'm thinking of must have happened in '94 or '96. I remember seeing footage of chairs and tables overturned and old people screaming something about Medicare. It would have been hilarious if it wasn't such a shame that these people thought they were in desperate enough circumstances to pull something like that.