CHARLES KRAUTHAMMER: Obama v. SCOTUS: Democrats were unpleasantly surprised by the strong constitutional argument against Obamacare.

With Obamacare remaking one-sixth of the economy, it would be unusual for the Supreme Court to overturn legislation so broad and sweeping. On the other hand, it is far more unusual to pass such a fundamentally transformative law on such a narrow, partisan basis.

Obamacare passed the Congress without a single vote from the opposition party – in contradistinction to Social Security, the Civil Rights Act, the Voting Rights Act, Medicare, and Medicaid, similarly grand legislation, all of which enjoyed substantial bipartisan support. In the Senate, moreover, Obamacare squeaked by through a parliamentary maneuver called reconciliation that was never intended for anything so sweeping. The fundamental deviation from custom and practice is not the legal challenge to Obamacare but the very manner of its enactment.

The president’s pre-emptive attack on the Court was in direct reaction to Obamacare’s three days of oral argument. It was a shock. After years of contemptuously dismissing the very idea of a legal challenge, Democrats suddenly realized that there actually is a serious constitutional argument to be made against Obamacare — and they are losing it.

James Taranto says they’re going through the Kubler-Ross stages of grief.

Related: Byron York: To Obama, legal precedents are all about politics.