Ezra Klein wrote a article about “No Labels,” a non-partisan group dedicated to “Not left. Not right. Forward.” I don’t have a qualm with either the group’s objective or Klein’s take. Actually, I think they are both very good. I do, however, have one minor issue with the article. It’s a nit-picky complaint but one that I think needs to be highlighted. So if it sounds like I’m beating a dead horse, I am. But I’m determined to shed light on this fact until somebody with more charisma, charm, and gravitas picks it up and runs with it.
Here’s Klein on congressional politics over the past sixty-years:

“But in Congress, in particular, it calmed. Political scientists have developed models to test congressional polarization, and the ‘50s, ‘60s and ‘70s were notable for the moderation of the two parties…The ‘80s, however, weren’t. That’s when party polarization accelerated. In the ‘90s, the rise was even faster. In the 1994 election, Republicans all but completed their sweep of the South, which dragged their party further to the right. Since 2000, polarization has only gotten worse.

American politics, in other words, has changed dramatically over the past 30 years. American political institutions have not. They’re built for consensus in an age of extreme polarization. There were more filibusters in 2009 and 2010 than in the ‘50s, ‘60s and ‘70s combined. Congressional Republicans almost forced the U.S. to default on its debt in 1995 and 2011. That would have been inconceivable in the middle of the century.” (my emphasis added)

Klein is mostly right. Congressional parties in the ‘50s, ‘60s, and ‘70s were more moderate. Also, those same parties were much more polarized in the ’80s, ‘90’s, and most especially the ‘00s to today. The one problem with this article is the bolded statement. American politics has of course changed over the past 60 years but placing blame on society misses the most relevant factor affecting polarization. That is: because Congress changed polarization increased. The models political scientists use to measure members’ ideology is based on how members voted on various issues. This includes final passage votes and procedural votes (i.e. votes on the rules that structure debate, amendments, etc for a particular bill on the floor). Party polarization has increased because procedural votes and party discipline on those procedural votes has climbed since 1973.

Put simply, the congressional reforms in the 1970s are the most powerful factor explaining party voting polarization in Congress. These reforms empowered the Speaker and party leaders. They used these powers to: one, control the chamber’s floor agenda through the Rules Committee; two, determine the terms of debate and amendments through restrictive rules; and three, enhanced their ability to enforce party discipline through patronage and committee assignments among others. So, the two-fold increase in procedural votes and discipline on those procedural votes accounts for roughly 70% of all voting polarization in the House, and roughly 60% in the Senate, since 1973. If we only look at final passage votes, the parties do not look nearly as polarized as we would assume. Of course factors like gerrymandering, partisan sorting in the electorate, and constituency change affect polarization. But they their combined influence pales in comparison to the institutional forces at work.

If you are crazy about polarization you must read Sean Theriault’s book.