In American politics, there are often calls to eliminate or change long-standing practices, such as the Electoral College. One repeated call in recent years has been to eliminate the filibuster, a legislative tactic used by the US Senate, for example, to delay or block a bill by formally objecting to the measure. To overcome a filibuster, a motion must be filed and a supermajority (60 percent or more) of support secured to force a final vote. But how much influence does the filibuster have in policymaking to begin with, and how would eliminating it affect government?
The answers, says Caltech professor of political science Alexander Hirsch, depend in part on ideological distribution of legislatures. Hirsch has been studying simple mathematical models of strategic behavior as part of a larger research agenda focused on the resources that legislators must invest to develop new high-quality policy proposals. In a recent paper published in the American Journal of Political Science, he argues that increased polarization in the US Senate could eventually convince centrists to eliminate the filibuster but for surprising reasons.
With co-author Ken Schotts, the David S. and Ann M. Barlow Professor of Political Economy at the Stanford Graduate School of Business, Hirsch investigated the role of so-called veto players—the lawmakers whose votes need to be swayed to approve legislation—in policy development.
Policymakers often spend large amounts of time and energy crafting high-quality proposals that they hope will appeal to the broadest range of their peers. Using mathematical models, Hirsch and Schott looked at how different levels of ideological attachment among policymakers and veto players can predict how much policymakers will invest in a proposal.
"We analyzed what policies people are going to develop in the model, who's going to be successful in the policy process, and how happy a senator sitting in the middle will be," Hirsch says.
Next, they studied these parameters under two institutional arrangements: The one we have, in which the Senate often requires a three-fifths supermajority vote to pass a bill, and a hypothetical one where all the elements of the model are kept the same but only a majority of votes is needed to pass a bill. They then also ran the model with extreme veto players who strongly associate with one party's ideology. Hirsch and Schotts found that moderate veto players make additional demands that can encourage productive policy development, but extreme ones make excessive demands that can eliminate it entirely.
"If there's a moderate amount of ideological disagreement in the legislature, then by raising hurdles [via a filibuster], you end up with one side being dominant, and it's the side that's really invested in changing the status quo," Hirsch explains, noting that, surprisingly, policies being crafted by highly invested legislators are actually good for centrists overall because a lot of effort is put into making them high quality, even if they are not exactly what centrists would want ideologically.
"But if the legislature becomes very polarized, having hurdles like the filibuster are bad because essentially now nothing is going to happen, and you're going to get even more gridlock than you would've gotten before. It just kills the policymaking development process entirely," he adds.
Hirsch compares the modeling process to building hypothetical worlds based on a particular setting, where parameters can be moved around to see what happens when certain things change. For example, the setting could be the US Senate with a two-seat Democrat or Republican majority. The researchers can then use those models to analyze real-world political phenomena and assess the models' predictions and assumptions through direct observation and other analytical tools.
"A lot of what we do with models is explaining to people in a really clear and analytically grounded way why things are more complicated than everybody out there is arguing that they are," Hirsch says. "We're not telling you the filibuster is good; we're saying you have to understand it's very likely that there are certain kinds of trade-offs involved with the presence of an institution like this and that it's not so obvious that everything will just be better if we get rid of it."
The filibuster first grew in popularity in the 1800s when opposers to a bill would debate it for so long that legislators ran out of time to vote. In 1917, senators adopted a rule to limit the debate with a two-thirds majority vote. By 1975, the Senate had reduced the supermajority to three-fifths, or 60 of the current 100 senators.
"If we don't understand why our government has elected to keep around a procedure that sometimes ties its own hands, then we are definitely going to miss something fundamental about what will happen if we change it," he notes.
Hirsch cautions both politicians and the public to avoid calling for big modifications to any long-standing government process or policy without analyzing the potential outcomes and says the team's model could be extended to examine broader questions about institutional design.
"In politics and institutions broadly, one major failure is not appreciating just how many unintended consequences there might be from changing an existing institutional arrangement," Hirsch says.
The American Journal of Political Science paper is titled "Veto players and policy development."
Alexander Hirsch
