The rich democracies that guarantee health coverage to all their citizens (i.e., basically all of them other than the United States) do so in one of two basic ways:
Either—Plan A—they create a government health insurance monopoly (like Britain, Canada, and France) or else—Plan B—they regulate the private insurance market so that all can and must buy (like the Netherlands, Switzerland, and Singapore).
Nobody disputes the constitutional power of the United States government to implement Plan A, the government health insurance monopoly. Such a monopoly was created in 1965 for over-65s, and it has been functioning now for nearly half a century.
Tomorrow, the Supreme Court will decide whether Congress may constitutionally enact a version of Plan B. Yes, true, some may devise ingenious ways to achieve universal coverage through private insurance even if the individual mandate is struck down. But as a practical matter, it seems to me highly unlikely that Congress will ever again recur to Plan B if the Supreme Court rules with opponents of the Affordable Care Act.
Much more likely is that the US will be cast back upon a starker alternative: either accept widespread non-insurance as a permanent feature of national life—or else revert at some future point to Plan A.
(Of course, it's theoretically possible that the Court might also attack Plan A tomorrow by ruling against the Medicaid extensions in the Affordable Care Act. Such a move however would require ripping up 75 years of constitutional law. Maybe my imagination is constrained, but I cannot see a closely divided court daring such an aggressive move with so little advance notice.)
I'm not a close Court watcher, and I have no prediction to offer about what will happen tomorrow. What I do think I can foresee are the implications of the choice before it. The mandate was an attempt to find a middle way. To say that is not to defend the ACA, a flawed piece of legislation that enlarges Medicaid too carelessly, that does too little to contain costs, and that relies too much on the wrong kind of taxes. It is only to say that if the Court tomorrow bars the way to a Plan B, the future looks even more polarized and radicalized than the recent past.