The one lesson that everyone should learn from reading the Supreme Court Affordable Care Act opinions is that we are all very poor seers when it comes to predicting the decisions of the United States Supreme Court. No one thought that Justice Roberts would be the deciding vote for the mandate, or that the Medicaid extension, which was uniformly upheld by all the lower courts, would be struck down in the Supreme Court by a 7 to 2 majority for its coercive nature. Earlier precedents on the point had suggested that the coercion argument was dead for all purposes, and yet it was revived with a vengeance.
On the other side of the line, the individual mandate was found to pass muster under the taxing power, which again was an argument that commanded no support when the case was heard in the lower courts. Yet the commerce clause argument, which was thought to be the stopper, was rejected by the Supreme Court on the now familiar grounds that Congress cannot require individuals to enter into an activity so that it could regulate it.
How this fits together no one can quite tell, but it is very clear that no one can harbor any illusions of a settled and coherent body of constitutional law.