From: "Frank Haber" 

OK, this is obviously the group of whom to ask this question.  Science
fiction short story, read in childhood -- title?  author?  Certainly feels
dyspeptic enough to be Heinlein, but I can't find it.  Has to be written
pre-1955.

Plot:  Semi-idyllic society where all elected officials must wear huge gold
medallions on their chest as a badge of office.  If five people
simultaneously get sufficiently pissed at an official, they push their
sacred buttons and a medallion explodes, offing said official.  The five
assassins are automatically identified, and must stand before the bar and
justify their crime/public_service.  There are complications.  End story.

--- BBBS/NT v4.01 Flag-4