When I wrote in the long post just below that I had not found any Democrats in the Congressional Record calling the individual mandate a tax on the floor of either house, maybe I was relying on the wrong search terms. John Hinderaker at PowerLine has a very good discussion of the often heavy reliance of the Democrats on the taxing-power rationale, and he concludes, respecting the chief justice’s opinion, that it “seems like a reasonable conclusion under existing authorities.”