… Many third-party supporters are convinced that Democrats and Republicans at the state and national level collude to restrict third-party ballot access and make fundraising more difficult for third parties and their candidates.
Regardless of other ways the major parties reinforce their electoral duopoly, their real baked-in advantage is purely structural; namely, the near-universal use on the national level and widespread use on the state level of single-member districts with plurality rule. [cont.]
Thomas F. Schaller, U. of Maryland, Baltimore County