Did Justice Roberts trade votes with Justice Kennedy in the Arizona decision handed down Monday?  I certainly hope so, for he would have struck a blow for constitutional conservatism. I will explain:

Many Court observers have expressed surprise at Chief Justice Roberts joining the majority opinion of Justice Anthony Kennedy, which struck down three of four provisions at issue with Arizona's S.B. 1070 and left the fourth on life support in terms of jurisprudence, and all but dead in terms of practice.

As Justice Scalia noted in a dissent that was animated even by Scalia standards, the Supreme Court's decision in Arizona et al. v. United States unquestionably dealt a serious blow to state sovereignty.  This has many conservatives asking how a purportedly conservative justice could have sided, particularly in such an important case, not just with Justice Kennedy, but with the Court's left wing.

Ben Shapiro at Breitbart speculates:

... it is entirely possible that Roberts joined with the liberal wing on this ruling in order to provide cover for the Obamacare decision to be handed down later this week. That decision will likely be 5-4, with Kennedy as the deciding vote -- and it has not been unheard-of at the Supreme Court level for a certain amount of vote-swapping to occur.

Noah Feldman at Harvard Law School likewise contemplates the possibility that a Roberts/Kennedy swap may have occurred. 

These are intriguing speculations.  So intriguing, in fact, that it may be worthwhile to discuss in brief detail compelling reasons that seem to have been overlooked by both Shapiro and Feldman why one should accept this as precisely what occurred in Arizona vs. United States.

Mr. Shapiro mentions providing cover for ObamaCare as possibly underlying a putative vote swap.  Many conservatives, in turn, have expressed outrage at the mere prospect that a justice who considers himself conservative would do such a thing.

But Justice Roberts could have made a reasonable case that doing so was not only consistent with constitutional conservatism, but required.  The starting point is to recognize that Arizona vs. United States was a "preemption case."  Preemption cases are unusual in that they represent a particular type of fusion between constitutional interpretation and statutory interpretation. 

As is true of many preemption cases, the emphasis was on statutory interpretation, not constitutional interpretation.  The resolution of the legal issues in the case depended heavily on comparing the statutory language of relevant federal law with that of the Arizona law, as well as comparing the policy objectives of each set of legal provisions.

Preemption cases almost invariably involve making specific and sometimes technical comparisons with respect to the area or areas of law in dispute in the case before the Court, in order to determine whether federal law supplants state law.

These observations lead to the idea that Justice Roberts may have figured that by agreeing with Kennedy, he was by no means committing himself to any particular outcome with respect to future preemption cases dealing with other areas of law. 

Furthermore, he may have reasoned (and Mr. Feldman did observe this) that siding with the rest of the conservative bloc would have resulted in a 4-4 tie that would function to affirm the Ninth Circuit's judgment that all four S.B. 1070 provisions must be struck. 

Justice Roberts could have continued to reason that since the Supreme Court would then not have spoken on the issue, future cases presenting substantially similar issues would likely arrive at a bench, including Justice Kagan, meaning Roberts would then be stuck with a 5-4 loss and an outcome the same as United States vs. Arizona in terms of area-specific constitutional doctrine.  

Moreover -- and this could have been pivotal for Roberts if vote-swapping with Kennedy really did take place -- a 4-4 decision would look terrible enough on its own, but how much more mutant would it look if combined with a 5-4 elimination of ObamaCare?

That is, the "cover" spoken of by Mr. Shapiro may well have comprehended a desire of Justice Roberts that the Court's perceived judicial integrity be maintained.  The chief justice of the Supreme Court of the United States is the principal custodian of the Court's institutional interests.  A vote swap would have functioned to do more than merely secure Justice Kennedy's vote in the ObamaCare case; it would have done so in a way likely to enhance the perceived public legitimacy of two of the most important and hotly contested cases of our lifetimes.

Just look at how the administration and their far-left MSM associates have received the decision.  What a tremendous victory for massive federal power!  Nope, no "judicial activism" there, is there?

Given the outcome in Arizona vs. United States, then, an administration loss in the ObamaCare case would in principle be much harder to characterize as mere "activist ideology."  While many leftists are bereft of principle, some do retain the semblance of it.

It is worth thinking too in this connection that of the two cases, the ObamaCare case is almost certainly the more important in terms of the future of constitutional conservatism.  ObamaCare implicates a federal takeover of one-sixth of the economy and much else besides.  Also, the Arizona outcome would appear to be much more amenable than a negative ObamaCare outcome to an alternative political resolution from practical as well as policy vantage points. 

If one thinks that Justice Kennedy was leaning against the individual mandate for reasons having nothing to do with Justice Roberts (and many are aware that there are good reasons for thinking this), then I hope that Chief Justice Roberts followed the logic of vote-trading in order to eliminate ObamaCare in its entirety, thereby enhancing the welfare of the Court and of the American people.  That would have been quite a blow for constitutional conservatism, would it not -- and all at no cost whatsoever to constitutional doctrine!   

Jason Kissner, Ph.D., J.D. is associate professor of criminology at California State University, Fresno.  You can e-mail him at crimprof2010@hotmail.com.