In Maybury vs. Madison, the 1801 case that arguably codified as law the role of the Supreme Court as a co-equal branch of government, Chief Justice John Marshall for all intents and purpose said the Constitution is what we say it is. In the recent ruling on ObamaCare, Chief Justice John Roberts, an "originalist," raised the bar by stating that a tax is what we say it is. It is important to remember that, through the entire process, we were told from President Obama on down that the individual mandate was a penalty, not a tax.
I remember listening to the radio on the first day of oral arguments, March 26. The justices dealt with this issue: Was the penalty imposed by the individual mandate in ObamaCare a tax? If it was, the case would run afoul of the Anti-Injunction Act, which ruled a tax cannot be challenged in court until someone has actually been forced to pay it.
The ObamaCare taxes don't take effect until 2014 and the court would have to throw out any court case challenging it because nobody has paid the tax yet. So the justices asked the government's lawyer, Solicitor General Donald Verrilli, if this is a tax. The government's lawyer replied in the negative.