This is a guest post by Michael Bailey. See also his earlier post on the ACA decision.
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Has Justice Kennedy moved dramatically to the right? Many believe so and Kennedy's behavior on the health care case certainly reinforces this view. I want to express a bit of skepticism about such claims.
First, these claims rest on justice ideology scores developed by Andrew Martin and Kevin Quinn. But these scores aren't great at tracking preference change over time. As the figure below shows, their method implies that the Court reached a conservative peak in the early 1970s, a time when the Court was creating constitutional rights to abortion and against the death penalty. Quinn has (with Dan Ho) expressed concerns about using these scores to compare preferences over time and I agree.
Second, it's not clear to me where the apparent shift to the right is coming from. The Court is not ruling in a "conservative" direction more often, as the graph above demonstrates. (There are questions about what is conservative, of course, but I think it's reasonable to take the coding in the Supreme Court database as a reasonable first cut for our purposes.) Moreover, from 2008 to 2010, when Martin and Quinn estimate that Kennedy shifted to the right, some high-profile conservative cases were not major shifts Kennedy. The conservative Citizens United decision continued Kennedy's jurisprudence since Kennedy had voted against the original Austin decision that Citizens United overturned. The Court's decision in the McDonald gun case was supported by more than 300 members of Congress, who signed as amici advocating the eventual outcome (including many moderates such as Senators Baucus, Feingold, Snowe, and Webb and Representatives DeFazio, Dingell, Giffords, and Oberstar; only 56 members of Congress signed on as amici for the liberal side).
Of the remaining high-profile ideologically charged cases from 2008 to 2010 there is a rough parity between liberal and conservative votes for Kennedy. By my count, Kennedy supported conservative outcomes on eight ideologically divisive cases (beyond what is discussed above and not counting this term, which does not factor in the Martin and Quinn scores). These must be taken against nine ideologically divisive cases where Kennedy voted liberally. That seems like the good old center-right Justice Kennedy we know rather than a new, hard-right one. (I'll share the specific cases I'm thinking of in comments.)
Third, the Court (which usually means Kennedy) is not that conservative compared to public opinion. Jessee and Malhotra (2012) polled Americans on specific Supreme Court cases, presenting them summaries of each position and asking which way the Court should have ruled. Eight of the nine cases they polled had conservative outcomes (Citizens United, Heller, Salazar, Ricci, Crawford, Baze, Parents Involved, Gonzales v. Carhart) and respondents were, on average, in agreement with the Court's decisions 71.6 percent of the time. (The one liberal decision in the survey (Hamdan) had the lowest level of popular support, at only 29.9 percent agreement). This is not proof that the Court hasn't moved to the right, but I think it provides helpful context. If the public agrees with the Court and the Court has indeed moved dramatically to the right, then the real story should probably be that the Court was dramatically more liberal than the public in 2007 before its shift to the right. I don't think that's true; hence my skepticism about the claim that the Court has dramatically moved right.
Why, then, do the Martin and Quinn scores show such a move to the right by Kennedy? I don't know and have been thinking about various possibilities. One idea is that there were a number of cases on Fourth and Sixth Amendment cases (e.g. Bullcoming, Melendez) in which Kennedy voted in a conservative direction and Scalia and Thomas voted "liberally" (in favor of defendants). (If you want to appear conservative, just vote conservative on cases where Scalia and Thomas vote liberally!) But are these votes really that conservative? On every one of these cases, Kennedy voted with Breyer (and sometimes other liberals). These votes seem to reflect less a shift to the right than the emergence of set of cases that aren't on the standard left-right dimension. (The flaw in this idea is Martin and Quinn approach does not rely on liberal and conservative codings, but instead essentially infers the liberal/conservative nature of a decision from its voting coalition. Hence the idea that the Fourth/Sixth Amendment cases are the cause of the shift in Kennedy's estimates is only a guess; these cases may actually get coded as conservative by the Martin and Quinn approach simply by virtue of Thomas and Scalia's votes.)
I've estimated Supreme Court preferences (which I'm calling "bridge estimates") based on models that use additional information to pin down preference change over time. While the Martin and Quinn model requires one to assume the spatial location of the Court's agenda does not change over time, my approach depends on an assumption that my additional information is right (more information is here). That's a (looong) discussion for another time perhaps. The upshot for now is that with this approach the median of the Court (who has been Kennedy since 2006) has been conservative, but nothing like the radically conservative Court depicted in the Martin and Quinn scores. (Note that I normalized each set of scores by subtracting the mean to make them more directly comparable.)
It is possible that Kennedy could move to the right in response to the apparent hard feelings generated by the ACA case. But through 2011 at least (which is the period covered by the Martin and Quinn scores) I'm not persuaded that he-and the Court-have moved dramatically to the right.
Finally, let me add a "meta" point. Martin and Quinn are incredibly smart scholars who have made huge contributions to the study of the Supreme Court. After they put their results out, the rest of us mull them over and think about if and how we can improve them. This post and the underlying paper are my two cents. Rinse, lather and repeat and hopefully we can make progress on interesting questions. This is how political science works.
