A while back, I took Gail Collins to task for characterizing Senate Democrats as “rabid guinea pigs in a thunder storm,” with the presumption that it would be hard for Democratic majorities to maintain discipline within their ranks. I pointed out that party unity has been increasing over time, that Democrats are lately more unified than Republicans, and that, in general, party unity is the rule, not the exception.
On Monday, CQ released its party unity scores for the 111th Congress, and—guess what?—the parties were really, really unified. Despite the size of the Democratic House and Senate majorities. Despite the influx of Blue Dogs. Despite the influx of rabid guinea pigs, or whatever. Indeed, Senate Democrats, Collins’ example, were the most unified they have been since 1956. Here is the CQ graph:
Here is a graph I made from the 1991-2010 data at the Washington Post’s U.S. Congress Votes Database. They calculate party unity a bit differently but the same basic story emerges: high levels of loyalty, generally increasing over time.
If you want to see the data since 1879, thanks to Nolan McCarty, Keith Poole, and Howard Rosenthal, scroll down to the bottom of the Polarized America page.
Narratives of declining party power and party unity are apparently quite appealing. Journalists love to seize on every instance of disloyalty and dissension. Here’s the story on Ben Nelson, for example. By contrast, a legislature where members’ votes are pretty predictable isn’t such an exciting story. But that’s the legislature we have.