On the eve of the Supreme Court’s decision on Obamacare, here’s a message to all the conservative activists out there, for whom this day has been a long time coming: Hats off to you! Unlike many of your opponents, you know how to build and sustain a political movement.

No, really: I mean it. Though the case against Obamacare that the Court is considering is a legal travesty, lacking in serious foundation, the moment is truly momentous. After thirty years of organizing, strategizing, and mobilizing, the conservative counter-revolution may be about to win its biggest victory yet: the striking down of a massive new government program, and, equally important, the overthrowing of a legal doctrine that Administrations of both parties have relied on for seventy years to regulate the economy.

Quite rightly, much of the discussion in the next few days will focus on the contents of the Court’s ruling, and its likely impact on the health-care industry, the rest of the economy, and the Presidential election. But before all that begins, it is worth taking a step back and surveying the historical landscape.