Closed Primaries and Party Support in Congress

Abstract

Nominating procedures in the American states rely on three types of primary elections: closed, open, and blanket. These systems vary with regard to the extent partisanship is injected into the process. The data show that members of Congress with the highest levels of party support in the House of Representatives are elected in states using closed primaries. However, this relationship between partisanship in office and use of the closed primary appears to result from the common determination of these two variables by regional differences and traditional patterns of interparty competition at the state level. In other words, the state systems that value partisanship the most will likely have closed primaries and elect representatives more likely to support their party.