This post is the fourth in our series on political polarization. The first three posts were by Nolan McCarty, Frances Lee, and Sean Theriault.
The distinction between ideological polarization and partisan tactics is valuable. Still, the empirical evidence suggests that it’s premature to let polarization off the hook as a key culprit shaping Congress’s legislative performance.
As I explore in Stalemate, the frequency of legislative deadlock increases as the parties polarize. Over the postwar period, congressional performance runs closely in tandem with the size and strength of the political center. As the figure below suggests, as legislative “moderation” declines, Congress and the president more frequently deadlock over the salient issues of the day.
In the figure, “moderation” captures the proportion of centrist legislators (lawmakers whose floor votes place them closer ideologically to the center of the chamber than to their own party median), divided by the ideological gulf between party medians. (I average House and Senate moderation scores to generate a “moderation” measure for each Congress.) Translation? When centrist legislators populate a Congress backed by relatively centrist parties, legislative agreement is frequently in reach on the big issues of the day. As more lawmakers move away from the political center and the parties diverge ideologically, Congress deadlocks more often.
To be sure, floor votes capture more than ideological differences. Moreover, factors beyond polarization generate gridlock. Divided party control of government has historically complicated dealmaking: building large majorities for change becomes harder when electoral and policy interests of Congress and the White House diverge. Bicameral differences also increase stalemate, as the two chambers — even when controlled by the same party– can disagree on policy means even when they agree on policy ends. (Case in point: The House in 2009 incorporated a public option into health care reform, the Senate opted for exchanges.) Once we take account of bicameral and inter-branch differences, as well as the degree of polarization, variation in legislative gridlock becomes quite predictable. The Great Society’s unified Democratic majorities in a period of ideological moderation yielded remarkably productive congresses in the 1960s. In contrast, frequent deadlock in 2011 and 2012 — on immigration reform, tax reform, climate change, and entitlement reform to name a few — stemmed directly from split party control of the chambers and branches, as well as historic levels of partisan polarization.
Why might polarization and deadlock run in tandem?
First, our political system requires broad, usually bipartisan, coalitions to adopt major policy change. Such coalitions are easier to build when a sufficient mass of legislators occupy the political center to bridge partisan and ideological divisions. As centrist, former senator John Breaux once put it, “you have to have someone to meet with. You can’t meet with yourself in a phone booth.”
Second, when elites and activist constituencies polarize, parties have electoral incentives to distinguish their records and positions, and they have a lesser incentive to compromise. Granted, legislative deals are possible even when there is no ideological sweet spot linking the parties. But as Frances Lee and I argue in the recent APSA Report on Negotiating Agreement in Politics, polarization and the partisanship that ensues more often encourage parties to fight messaging wars than to negotiate. Unless one or both parties fear public blame for blocking popular measures, polarization often encourages the parties to hold out for a whole loaf, rather than to settle for half.
No surprise then that legislating in polarized times sometimes means hardly legislating at all. Learning to legislate in such times should be high on lawmakers’ to-do list.