Negotiating agreement in the U.S. Congress is difficult by design Members of the U.S. Congress are chosen by constituencies that are politically and electorally heterogeneous. As such, members arrive in the two chambers with diverse preferences, priorities, and electoral security. All of these factors can combine to make agreement elusive. The goal of this project is to assess and analyze how effective congressional parties and their leaders are at negotiating the parties’ twin goals of electoral success and policy enactments from 1957 – 2016. I will also be able identify characteristics of effective party leaders.