Minority Party Capacity in Congress

When, and under what circumstances, are congressional minority parties capable of influencing legislative outcomes? We argue that the capacity of the minority party to exert legislative influence is a function of three factors: constraints on the majority party, which create opportunities for the minority party; minority party cohesion on the issue at hand; and sufficient motivation for the minority to engage in legislating rather than electioneering. Drawing on data on every bill considered in the House of Representatives between 1985 and 2006 and case examples of notable lawmaking efforts during the same period, we show that our theory helps predict which bills are considered on the House floor, which bills become law, and the substance of policy-making outcomes. Our findings have important implications for theories of congressional party power and our understanding of minority party influence on Capitol Hill.