It is not judicial activism - the Administration argued before the court this was a tax and that is what the court ruled on.
The court just declared Obama and the Democrat controlled (at the time) Congress to all be liars.
Correct me if I am wrong, but I thought that the Court was supposed to act upon what Congress actually passed. If you can show me where in that 2,700 monstrosity it was referred to as a tax, then I will agree with you. Otherwise, Roberts was ruling on what the ACA’a lawyers argued, not what was in the bill. And that, my friend, is judicial activism.
It is beyond question that the Administration case was, when it was convenient, that it WAS a tax, and when it was convenient, that it was NOT a tax.
May I suggest these observations from the vaunted "oral argument" phase of the case:
U.S. Solicitor General Donald Verrilli used the phrase “tax penalty” multiple times to describe the individual mandate’s backstop. He portrayed the fee as a penalty by design, but one that functions as a tax because it’s collected through the tax code.
“General Verrilli, today you are arguing that the penalty is not a tax. Tomorrow you are going to be back and you will be arguing that the penalty is a tax,” said Justice Samuel Alito, in one of the few laugh lines throughout the 90 minutes of argument Monday.
And, as proof enough to me (now) that "oral arguments" are just a bunch of pretty words for us yokels:
The justices, particularly the four Democratic-appointees, and Justice Antonin Scalia, appeared skeptical that the fine constitutes a tax.
http://www.therightscoop.com/day-1-listen-to-the-supreme-courts-oral-arguments-on-obamacare/