Former Roberts clerk: What's really behind his surprising decision

The key move in Roberts’ opinion is his conclusion that the individual mandate is actually a sort of tax, and therefore constitutional by virtue of Congress’s unquestioned power to tax. That allows the mandate to stand, yes — but effectively makes the mandate sui generis, and thereby denies the government a new source of regulatory power.

This is why: Roberts does not say that the government may now regulate anything it likes by calling the regulation a tax. He says this mandate can be read as a tax in these circumstances — that is, in light of the fact that it would be unconstitutional on any other ground and the court is supposed to avoid finding statutes unconstitutional if it can — and on these grounds: because it is administered by the IRS through the tax code and operates in many respects like a normal tax. Only if future regulatory schemes can meet all these criteria would they be valid under the taxing power. Yet Roberts does not give a single example of any such scheme — and we know for a fact, because they have told us repeatedly, that members of Congress would never have voted for this regulation if they had believed it was a tax.

Making the mandate a tax has at least one other effect. It makes repeal easier. Now that the mandate has been deemed taxation, it can likely be jettisoned through use of the reconciliation process — meaning the Senate will need to muster only a bare majority for repeal, not 60 votes.