They may fail as a sustainable political party, but they can still have an impact on elections. Ross Perot got 20% of the vote, in 1992, which were probably more republicans than democrats, and probably aided Bill Clinton’s victory. And of course there is the theory that Ralph Nader’s Green Party candidacy may have peeled off enough democrat votes in Florida in 2000, since it was less than 600 votes that Gore lost by.