I’m sure he’ll heh-indeed some Megan McArdle counter-theory soon enough, but for now Kevin Drum puts it well:
If the court does overturn the mandate, it’s going to be hard to know how to react. It’s been more than 75 years since the Supreme Court overturned a piece of legislation as big as ACA, and I can’t think of any example of the court overturning landmark legislation this big based on a principle as flimsy and manufactured as activity vs. inactivity. When the court overturned the NRA in 1935, it was a shock—but it was also a unanimous decision and, despite FDR’s pique, not really a surprising ruling given existing precedent. Overturning ACA would be a whole different kind of game changer. It would mean that the Supreme Court had officially entered an era where they were frankly willing to overturn liberal legislation just because they don’t like it. Pile that on top of Bush v. Gore and Citizens United and you have a Supreme Court that’s pretty explicitly chosen up sides in American electoral politics. This would be, in no uncertain terms, no longer business as usual.
I blame Democrats for blocking the nomination of Robert Bork. That’s what started all of this.