Judicial Judo: The Chief Justice and Obamacare
Nobody expected it. Most observers thought that the conservative majority of the Supreme Court would at least throw out the mandate for everyone to have health insurance. And if even that provision survived, it would have to be Justice Kennedy providing the deciding fifth vote, as he has so many times since the retirement of John Paul Stevens.
Instead, what we got was Chief Justice Roberts going with the liberal bloc for the first time in a 5-4 vote, while Kennedy wrote the dissent for the four conservatives. Moreover, Roberts constructed his majority opinion on unexpected grounds. While rejecting the Obama administration's primary argument that the individual mandate was a legitimate exercise of the constitutional power to regulate interstate commerce, he refused to go along with the conservative in concluding that the whole law should be thrown out.
Instead, he took up the backup argument that the mandate could also be construed as a tax which lies within the acknowledged authority of Congress to impose taxes. On this basis he affirmed that the whole law is constitutional, while explicitly refraining from any judgment about its merits as public policy (a question that he referred to the elected representatives of the people, that is, Congress).
So, what gives? I believe that what we've seen is a kind of "judicial judo," where the force of the adversary is used to defeat that adversary. Whether it will work remains to be seen.
Had Roberts done the predictable and sided with the conservatives, the law would have gone down. That is probably the outcome he would have preferred. But it would have further confirmed that the Court is divided into polarized, increasingly partisan liberal and conservative blocs. Ever since Bush v. Gore in 2000, many on the left have seen the Court's majority as essentially another arm of the Republican Right. By switching sides, Roberts undermines that narrative, and maintains the precarious legitimacy of the Court as a politically independent arbiter. As Chief Justice, it is his unique responsibility to protect that institutional legitimacy, at a time when excessive partisanship has gravely undermined that of Congress.
Moreover, Roberts' opinion serves conservative ends in the long run precisely by blocking the conservatives in the immediate case. For he affirms Obamacare's constitutionality on tax grounds that do not represent an expansion of federal prerogatives, while rejecting the extension of the Commerce clause to justify the individual mandate. He thus adopts a position of "judicial restraint" in refusing to countenance a novel use of the Commerce clause, by allowing a law passed by Congress to take effect, and by explicitly refraining from any judgment of its merits as policy. But he approves the law on the narrowest possible grounds, making more difficult any future expansion of federal authority.