This graph is from “Keith Poole”:http://www.voteview.com/bio.htm at the “Voteview blog”:http://voteview.spia.uga.edu/blog/?p=1482. What the graph shows is the extent to which the ideology of Congressmen (estimated based on their previous votes) correlates with their votes on the budget deal. The right plot shows the Congressmen the model predicted wrongly (blue votes to the right of the cutting line and red ones to the left). Poole writes:
bq. The plot reveals that ideology (which is represented by the first dimension) was a major component of the budget deal vote. Opposition was isolated to the ideological extremes of each party-Democrats furthest to the left and Republicans furthest to the right. This configuration is an example of “two ends against the middle” voting, a pattern “we also found in the March 15 House”:http://voteview.spia.uga.edu/blog/?p=1312 vote on a three-week Continuing Resolution.
This is indicative of the kind of deal reached by a compromise between party leaders rather than a minimum winning coalition approach where the median house member is the pivotal player. In such a deal, House Republicans would have picked up some centrist Democrats and only liberal Democrats would have voted against. Keith also “reports”:http://voteview.spia.uga.edu/blog/?p=1482 that tea-party caucus members and freshmen Republicans were more likely to be among the no-voters than other Republicans.
Empirical spatial models only tell us something about who is likely to vote for or against a bill. They don’t reveal much about the strategic nature of the bargaining process. It is easy to say ex post that this was an obvious deal. Yet, bargaining theory tells us that even if both parties had a strong incentive to avoid a shutdown, they also had strategic incentives to misrepresent just how much they would be willing to give up in order to get there. Someone had to give in at the deadline and I agree with “Sarah”:https://themonkeycage.org/2011/04/congressional_dealmaking.html that it looks like the Democrats were just a bit more eager to get a deal done before the deadline.