Polarization in the US Congress

Abstract

Political polarization can be defined generally as “movement away from the center toward the extremes” in policy preferences. There is general scholarly agreement that lawmakers in the United States Congress (USC) increasingly “appear to represent relatively extreme support coalitions rather than the interests of middle-of-the-road voters”. While this definition of is broadly accepted, in practice, congressional polarization is commonly estimated from roll call votes and bill cosponsorship data. Such data, however, cannot uncover whether members across the aisle are in disagreement over programmatic details of bills or something more fundamental, such as policy agendas and values.