Replication Data for: A House Divided? Roll Calls, Polarization, and Policy Differences in the U.S. House, 1877–2011

Studying political conflict in legislatures is necessary for understanding many issues related to governance, but changes in who serves and what is debated creates difficulties for characterizing that conflict over time. Focusing on the enduring issue of civil rights in the U.S. since Reconstruction, we show that current methods and measures used to characterize elite ideological disagreements are hard to interpret and/or reconcile with widely accepted historical accounts because of their failure to adequately account for the policies being voted upon and the consequences of the iterative lawmaking process. Incorporating information about the policies being voted provides a starkly different portrait of elite conflict -- not only are contemporary parties relatively less divided than is commonly thought, but the conflict occurs in a smaller, and more liberal, portion of the policy space. In addition to revising commonly held beliefs about the nature of elite conflict occurring since Reconstruction, our argument also highlights several substantive and methodological issues with using measures based on elite behavior to compare political conflict and polarization across time.