I, too, think it's a lousy law; but ...
... Specifically what in the Constitution has been violated?
First: The executive branch nor the SCOTUS exist to WRITE law. Both have rewritten the letter of the law.
All revenue generating measures must originate in the House. The “tax” was added in the Senate.
Second: to say you have to buy something (just for breathing) but your neighbor doesn’t have to have it—not because he has a religious (1st Amendment) objection, but because his union cut a deal....is a violation of the Equal Protection Clause. It is not up to Obama to make exceptions.
Deadlines set in this “established law” are being changed on the whim of the executive branch. Either it is law, or it isn’t.
The law requires that which is not possible, that people use a defective system to sign up for something by a given deadline.
The Origination Clause.
Obamacare is a tax. Tax bills originate constitutionally in the House. Obamacare was written Harry Reid's 'Rat Senate.