In 2011, Gallup’s polling showed that President Obama averaged an 80 percent approval rating among Democrats and 12 percent among Republicans, making his third year in office one of the most polarizing on record. For a candidate whose campaign promised an era of post-partisan unity, it must be a disappointing reality check.
But on Friday, political scientist Keith Poole released a study that probably cheered the White House. According to his highly respected classification system, Obama is the most moderate Democratic president since World War II. Which raises a question: How can Obama simultaneously be one of the most divisive and most moderate presidents of the past century?
Ezra Klein is the editor of Wonkblog and a columnist at the Washington Post, as well as a contributor to MSNBC and Bloomberg. His work focuses on domestic and economic policymaking, as well as the political system that’s constantly screwing it up. He really likes graphs, and is on Twitter, Google+ and Facebook. E-mail him here.
Poole’s study is based on a system for sorting politicians known as “DW-Nominate.” But DW-Nominate doesn’t directly measure ideology. Instead, it measures coalitions. It’s got pretty much every roll-call vote taken between 1789 and December of last year. It looks to see who votes together and how often. The assumption is that the most ideological members of both parties will do the least crossover voting. And it works. Its results line up both with common sense and alternative ways of measuring ideology, like the scorecard kept by the American Conservative Union.
Over the past century, DW-Nominate has shown a steady increase in congressional polarization. Democrats have moved to the left while Republicans have moved to the right. But Republicans have moved a lot further than Democrats. “Republicans in both chambers are polarizing more quickly than Democrats,” said Sean Theriault, a political scientist at the University of Texas at Austin. “If the Democratic senators have taken one step toward their ideological home, House Democrats have taken two steps, Senate Republicans three steps and House Republicans four steps.”
Political scientists call this “asymmetric polarization,” and there’s evidence of it all around us. Forty years ago, for instance, zero Republicans in Congress had signed a pledge to oppose tax increases in any and all circumstances. Today, almost all of them have. There’s no corresponding pledge on the Democratic side.
DW-Nominate rates presidents by processing Congressional Quarterly’s “Presidential Support” index, which tracks roll-call votes on which the president has expressed a clear position. The system then rates the president by looking at the coalitions that emerged in support of his legislation. In essence, it judges the president’s ideology by judging the ideology of the president’s congressional supporters. So how, in an age of incredible congressional polarization, could this system rank Obama as a moderate?
There are a few answers. One, says Poole, is that Obama is very careful about taking positions on congressional legislation. In the 111th Congress, he only took 78 such positions. Compare that with George W. Bush, who took 291 positions during the 110th Congress, or Bill Clinton, who took 314 positions during the 103rd Congress. So part of the answer might be that, with the exception of high-profile bills such as health-care reform, Obama is hanging back from most of the congressional squabbling.