In a new white paper, Trapped in a Two-Party System, Steven L. Taylor, Professor Emeritus of Political Science at Troy University, demonstrates that the two party system of the United States is truly exceptional—and not in a good way. No other major democracy has such complete dominance by only two parties. When polled, voters say they want more choices, and they have been consistent in that preference for decades. Yet when voting, voters cast their ballots for Republicans and Democrats, not for new parties.

The root cause of the disconnect lies in our electoral system: The way we conduct nominations and elections. Our exclusive use of winner-take-all elections in congressional and state legislative elections suppresses parties. Most other countries abandoned winner-take-all in favor of proportional representation decades ago, and countries with proportional representation tend to have more viable parties than those that retained winner-take-all. 

However, even other countries with winner-take-all have more parties than the United States does. That is significantly because in the United States, any serious candidate can capture the Republican or Democratic nomination in the primary election—No other country uses primary elections as systematically as the United States. In other countries, parties control their nominations and keep out candidates who are not aligned with the party platform. With primary elections, on the other hand, would-be challengers to the two major parties have a far easier path to office by winning the Republican or Democratic nomination than they would by starting a new party.

To achieve a more robust multiparty system, we should find a way of conducting elections that escapes the party-suppressing effects of winner-take-all and primary elections. Professor Taylor puts forward one practical example: open list proportional representation. The use of proportional representation would reduce the threshold for smaller parties to win seats. Meanwhile, the use of an open list ballot would move primary election competition into the general election, by allowing voters to directly vote for, and help elect, their preferred candidate within a party list.