Well, he was, according to Jonathan Cohn in the New Republic:
What’s more important, for the rest of us, is that Obama corrected and clarified the misstatement one day later. Striking down this sort of economic legislation, Obama said, would be unprecedented in the modern era—and reminiscent of the early 20th Century, when the Court threw out multiple pieces of economic regulations from the Progressive Era and then the New Deal. Here's how Obama put it, word for word:We have not seen a Court overturn a law that was passed by Congress on a economic issue, like health care, that I think most people would clearly consider commerce—a law like that has not been overturned at least since Lochner. Right? So we’re going back to the ’30s, pre New Deal.
This claim has also drawn criticism from the right. But it is totally defensible.
I've tried to make the case previously for why a decision striking down even part of the Affordable Care Act would be so brazen and unjustified (and quite unlike more defensible instances of judicial activism, such as Brown v. Board of Education): It'd be a five-to-four vote, along party lines, overturning a sweeping legislative initiative on what would be, at best, shaky constitutional arguments. That hasn't happened since those early New Deal cases, just as Obama suggested.
Although Cohn dismisses their importance, we have to say that the president's account includes some errors. The Lochner case, for example, had nothing to do with the commerce clause, and so it, of course, had nothing to do with the power of Congress to regulate under that clause.
The Lochner case negated a state law regulating the number of hours that could be worked by bakers, and it was decided according to the liberty of contract the Court found in Due Process Clause of the Fourteenth Amendment.
The opinion of the Court in Lochner has generally been discredited as a precedent because it failed to give the benefit of the doubt to the state law as a reasonable regulation (see Justice Harlan's dissent, not the mess written by Justice Holmes). "Liberty" became an aggressive tool of judicial activism.
There are some libertarians these days who want to rehabilitate Lochner, applying the test Randy Barnett calls the "presumption of liberty" to every law national and state. Law is unnecessary unless a convincing argument is given otherwise. Barnett, in this spirit, applauds the Court's decisions in both Lochner and Roe v. Wade as protecting indispensable dimensions of liberty against tyranncial state majorities.
Not many Americans, of course (and certainly neither the President nor Governor Romney), would be for a Court that consistently "activist." Governor Romney, but not the President, regards Roe as the aggressive result of judicial activism. From a very consistently libertarian view, both Obama and Romney are quite selective in what they call judicial activism.
But the "affordable care" mandate case won't be decided that way. If the mandate and perhaps more of the law are struck down, it will be because Congress has no power to compel an act of commerce under the commerce clause.
That will mean, of course, that the state mandates are constitutional under the "police powers." The commerce clause is not meant to limit state legislatures. Romney will, in a way, be vindicated in his assertion that what Massachusetts may do Congress may not. (Yes, I realize, that he also said a couple of times that he was for the national mandate, just as I realize he never has given the correct constitutional reason for distinguishing between state and national mandates.)
The consistent libertarians want the Court to strike down mandates both national and state as equally offenses against liberty. And that consistency would be in the genuine spirit of Lochner. But I will be astonished if that happens. I will be more than willing to call that judicial activism.