On the reason why – sorta – to have a fourth party:
…third parties attract all the crazies — all the people who give up on the social niceties (read: “sanity”) — needed to be a member of one of the major parties. For instance, libertarians have seemingly rational stances of fiscal conservatism and social liberalism, but who does the Libertarian Party nominate? Candidates who dye themselves blue and like to have their promotional pictures taken with ferrets.
This is less of an exaggeration than you might think. In fact, it’s not an exaggeration at all.
(H/T: Instapundit)