Good question.

Uh, that's what I want to know.

How did so many commentators predicting this would be a slam dunk for the Obama administration get it so wrong?

Many people have blamed Obama Solicitor General Donald Verrilli’s poor defense of the law for the sudden jeopardy Obamacare finds itself in, and there’s no denying he was unprepared to answer questions that we’ve known for months would be central to the case.

But there’s another explanation for the botched prediction: Simply put, legal observers of all stripes, and Obamacare’s proponents, including those in the administration, badly misjudged, and were too overconfident about, the tone, attitude and approach that the court’s conservative bloc, particularly Justice Scalia, would take towards the administration’s arguments.

This seems to be an ongoing problem. Simple rule: never understimate the wingnuttery and partisan hackishness of the modern right.