It seems that President Obama's own claims that the health care mandate wasn't a tax is causing a problem for his lawyers before the Supreme Court today:

"The president said it was a tax, didn't he?" Scalia asked.

[ U.S. Solicitor General Donald] Verrilli argued, "The President said it wasn't a tax increase because it ought to be understood as an incentive to get people to have insurance. I don't think it's fair to infer from that anything about whether that is an exercise of the tax power or not."

But later in this strain of arguments, Chief Justice John Roberts asked, "You're telling me (Congress) thought of it as a tax, they defended it on the tax power. Why didn't they say it was a tax?"

Verrilli responded, "They might have thought, Your Honor, that calling it a penalty as they did would make it more effective in accomplishing its objective."

Roberts evidently stunned by the weakness of the argument, shot back "Well, that's the reason? They thought it might be more effective if they called it a penalty?"

A stumbling Verrilli started out, "Well, I — you know, I don't — there is nothing that I know of that — that illuminates that, but certainly -­"

Obviously, the reason they didn't call it a tax is because it would have been politically unpopular. But that's not really something you can say in front of the Supreme Court without couching it in heavy legalese. Verrilli's linguistic stumble is terrible news for Obamacare. The media's opinion after today's arguments is that the mandate is "on the ropes" or "in trouble," and that the arguments were a "train wreck."