Speaking of political party slander, I am reminded of the 2000 “subliminal rats” fiasco:
“Fiasco” seems more accurate than “scandal”, since nothing seemed to come of the matter (not that anything comes from most scandals).
Update: “Subliminal Rats” would be a great punk rock band name. Somebody take action, I will sign over all rights.
Update 2: Link: http://news.bbc.co.uk/2/hi/in_depth/americas/2000/us_elections/election_news/921830.stm