Will Wilkinson has written an excellent post countering Ezra Klein’s case against the filibuster, and he cites one of my favorite books, Jeremy Waldron’s Law and Disagreement.

The more dangerous temptation is not to pretend an opposing view does not exist, but to treat it as beneath notice in respectable deliberation by assuming it is ignorant or prejudiced or self-interested or based on insufficient contemplation of moral reality. Such an attitude embodies the idea that since truth in matters of justice, right, or policy is singular and consensus is its natural embodiment, some special explanation — some factor of deliberative pathology, such as the lingering taint of self-interest — is required to explain disagreement, which explanation can then be cited as a reason for putting the deviant view to one side.

It’s worth noting, however, that Law and Disagreement is a powerful indictment of the idea of judicial review and a defense of majoritarian democracy. The book avoids institutional questions, yet it is easy to see its central arguments as bolstering the case for direct democracy. I’m not sure what Waldron would make of the filibuster or for that matter the U.S. Senate. My sense is that liberals like Klein and Matt Yglesias fundamentally object to the composition of the U.S. Senate itself, seeing it as an undesirable departure from the principle of one man, one vote. And so ending the filibuster is a kind of second best solution designed to lower the barriers to sweeping legislative initiatives.

During the debate over the nuclear option, I thought it was pretty that the precedent would ultimately be used by the left to pursue longstanding legislative ambitions. I was agnostic at the time. Now, however, I find myself persuaded by Jay Cost’s case against the case against the filibuster. Cost asks,

if the parties are more unrelentingly partisan now than in ages past, is it prudent to lower the barriers that prevent them from enacting sweeping policy changes?

After noting that the Senate has grown more politically polarized, Cost argues that the filibuster helps prevent extreme policy shifts.

This points to a highly beneficial purpose the filibuster can serve. Per Klein, it is indeed an obstructionist tool, but it is also a way to promote moderate policies, even as the parties have become more ideologically extreme. In other words, thanks to the filibuster, an ideologically extreme majority party cannot simply enact its policy preferences as it sees fit. Instead, it must either find common ground with some on the other side, or do nothing. In other words, the filibuster has an effect similar to that of a large body of water on the climate of the neighboring coast, keeping the temperature from getting too hot or too cold.
Think of it this way. When Democrats are in charge, they will endeavor to pull the policy needle to the left. To succeed, they will have to negotiate with the pivotal legislator. If the status quo is retained, that would be the 60th senator, who will sustain a filibuster if he is not satisfied. On the other hand, if the filibuster is eliminated, the Democrats will only have to appeal to the 50th senator, who will by definition be more liberal than the 60th. Policy outputs would thus shift leftward, perhaps dramatically so. The same goes for the GOP. When Republicans are in charge, they must find common ground with the 60th senator, which will result in much more moderate policies than what we’d see if the filibuster is eliminated. I would point to the 109th Congress. If George W. Bush had to appeal to Norm Coleman rather than Mary Landrieu, the Republicans would have gotten plenty more done, and their policy outputs would have been much more conservative.

Like most sober analysts, Klein has noted that Republicans will have an extremely difficult time repealing Democratic health reform legislation as the filibuster poses an insuperable obstacle. But once the filibuster goes, the landscape starts to look very different.

The consequences of extreme policy shifts could be baleful, particularly if they start to violate the norm of anti-entrenchment. What if every congressional majority passed campaign finance regulations designed to weaken the opposition? And on the off chance the opposition managed to overcome the resulting handicap, who doubts that they would retaliate in kind?

If nothing more than a simple majority is necessary for sweeping changes, what stops a newly victorious party from undoing all the reforms implemented by the old majority, and instituting its own set of big changes? What would be the long-term consequences of that? If every biennial or quadrennial election brought the prospect of big changes in public policy – how could we practically plan for the future? We all expect things in 2013 to be generally the same as things in 2009. Eliminate the filibuster, empower a bare majority to impose ideologically extreme policies, and that expectation could become unreasonable.

One could reply that this kind of behavior is unimaginable, or that it would represent the death knell of our democracy. But of course part of the impetus for the Democratic health reform plan is to entrench universal health coverage as a responsibility of the federal government, thus permanently altering the size and contours of the federal government and, in theory, giving parties of the left a lasting political advantage as the guarantors of the new entitlement. I don’t think of this as an “anti-democratic” impulse.

Extreme policy swings of the kind Cost describes defined the politics of many Latin American democracies that proved extremely fragile in the postwar era. In the United States, the cooperative norms that we rely on to preserve constitutional democracy depend on institutions like the filibuster. While it’s doubtless true that the filibuster is invoked more frequently now than during the Johnson administration, it’s also true that other checks existed on extreme policy swings, including the fact that the political parties were more internal divided on ideological grounds. It’s only natural that use of the filibuster would evolve along with the broader political environment.