How many of Chief Justice Roberts' brethren signed onto his finding that "the individual mandate is not a valid exercise of Congress’s power under the Commerce Clause and the Necessary and Proper Clause"? None.
Justice Ginsburg, writing for the four liberal justices with regard to the mandate, concurred with Roberts' finding that the mandate was a constitutional exercise of Congress's taxing power, but dissented strongly on the Commerce Clause question. Justices Alito, Kennedy, Scalia and Thomas officially concurred with no part of Roberts' decision, though their reasoning with regard to the Commerce Clause mirrored his. And of course, the Chief Justice's own finding that the mandate is constitutional rendered his Commerce Clause judgment moot with respect to the fate of the individual mandate.
A question, then, for legal scholars: does the finding that Congress cannot regulate inactivity have any force of law for future cases?
I personally believe that 1) the liberty-squelching mandates that conservatives purport to fear are a chimera; democratic pressures alone will forestall them, as they have forestalled state purchase mandates; and 2) the future import of all parts of this decision will depend mainly on the future makeup on the Court -- that is, in the near term, on the outcome of the presidential election.
But I'd still like to know: other than opening a window on the thinking of five sitting conservative justices, does Justice Roberts' attempt to limit Congress's Commerce Clause power matter?
Postscript: note answer to this question in comment below by a well-informed healthcare attorney.