The Green Party holds its convention. Ralph Nader ran for the presidency as a Green in the 2000 election. By doing so, he brought up many questions of social choice—some would say deliberately. Was Nader a spoiler candidate? Were Nader supporters casting sincere votes for him? Would other voters who liked his positions be hedging their bets and voting insincerely if they chose another candidate? Mark Leffingwell/AFP/Getty