O Other, Where Art Thou? Mass Support for Multiparty Politics in the United StatesThis is a White Paper prepared for presentation at the Southwestern Social Science Association meeting in New Orleans, Louisiana - March 2002 which lays out carefully researched statistical analysis of considerable support for the creation of a multi-party political system in this country - (requiring Proportional Representation election system as the logical extension).
http://plsc.uark.edu/csr/working/papers/paper14.pdfThe primary questions posed in formulating this test and theory (based on data collected in two states)" Which Citizens want parties other than just Democrats and Republicans to be competitive in the United States?" and " Where would such an "other party" find electoral support if rules allowed it to win seats?"
It would be interesting to see an updated analysis following the 2004 elections, imo.