Being backed by extended party networks can mean a greater chance of electoral success for a Congressional challenger

Political parties play a central role in democracies, helping to mediate between citizens and governing elites by running candidates for office who promise to pursue policy programs. But what if “the party” is really more of a collection of interest groups than a traditional party organization? Using data from US congressional elections and campaign finance, Bruce Desmarais, Ray La Raja and Mike Kowal show that parties are networks of partisan groups that converge on select groups of challengers. They explain that parties in the U.S. have become so distinctive and polarized, because they represent unique coalitions of policy demanders that influence the ideological composition of Congress.