Here’s a letter to the New York Times:
Perhaps Laurence Tribe is correct that Obamacare doesn’t violate the Constitution as that document has been interpreted since the New Deal (“On Health Care, Justice Will Prevail ,” Feb. 8). It is, however, precisely this expansive interpretation that is now at issue.
No less a left-liberal legal lion than Yale’s Bruce Ackerman admits that the Constitution had to be amended in order for New Deal policies to pass constitutional muster. But this ‘amendment’ was not done through Article V procedures (as explicitly provided in the Constitution); rather it was done by a Supreme Court bullied by a U.S. President. Here’s Ackerman: “Roosevelt and the New Deal Congress had not chosen to codify their new constitutional principles by enacting a few formal amendments, of the sort contemplated by Article Five. Instead, the President and Congress left it to the Justices themselves to codify the New Deal revolution in a series of transformative judicial opinions, threatening to pack the Court unless it accepted this novel constitutional responsibility.”*
Prof. Ackerman regards this historical event as being a legitimate instance of constitutional amendment. Many other Americans – rubes that we might be for insisting that the actual words of the Constitution itself be taken literally – disagree.
Donald J. Boudreaux* Bruce Ackerman, We the People: Foundations  (Cambridge: Belknap Press of Harvard University, 1991), p. 119.
If in the opinion of the People the distribution or modification of the Constitutional powers be in any particular wrong, let it be corrected by an amendment in the way which the Constitution designates. But let there be no change by usurpation; for though this, in one instance, may be the instrument of good, it is the customary weapon by which free governments are destroyed.(HT Jim Agresti)