None other than Obama, as the administration prepares its case in defense of legal challenges to healthcare legislation.

A legal egghead sums it up well:

Jack M. Balkin, a professor at Yale Law School who supports the new law, said, “The tax argument is the strongest argument for upholding” the individual-coverage requirement.

Mr. Obama “has not been honest with the American people about the nature of this bill,” Mr. Balkin said last month at a meeting of the American Constitution Society, a progressive legal organization. “This bill is a tax. Because it’s a tax, it’s completely constitutional.”

Remember when the president rejected that notion.