The first I learned about the U.S. Constitution was back in high school in the 60s, where in addition to getting introduced to the document itself we read some excerpts from the Federalist Papers.  I'm pretty sure we read Madison's very famous Federalist 45, from which the money quote is:

The powers delegated by the proposed Constitution to the federal government, are few and defined. Those which are to remain in the State governments are numerous and indefinite. The former will be exercised principally on external objects, as war, peace, negotiation, and foreign commerce; with which last the power of taxation will, for the most part, be connected.

In my high school, nobody mentioned that during the New Deal the federal government had slipped free of the bonds of this tedious limited powers thing, largely (but not entirely) through a Supreme Court case called Wickard v. Filburn.   I figured that out when I got around to learning constitutional law in a semi-serious way in law school eight or so years later.  I say "figured it out" because it was never put quite that way in Larry Tribe's con law class.  Hey, of course the Constitution has had to be adapted to the modern world; now can we please move on to 43 cases applying footnote 4 of Carolene Products?  Funny, Madison et al. somehow thought this limited powers thing was pretty important.  How old fashioned!

Well, even without limited powers, we do still have the bedrock principle that to be binding on the people a law must be passed by both houses of Congress and either signed by the President or passed by two-thirds majorities of both houses over his veto.  Or has that principle also been declared inoperative?  Actually, that principle has been under severe attack as well, again going back to the New Deal.  First it was the profusion of "agencies," some of them not even answerable to the President (try to find that one in the Constitution), and then the even greater profusion of statutes turning over more and more authority to one or another agency to add to the laws by creating "regulations."  But really only in the last few years has it become the fashion for Congress to pass multi-thousand page statutes taking over vast swaths of the economy, and where the statutes despite their length omit most of the operative provisions and delegate the task of coming up with those to unelected agency bureaucrats.  Dodd-Frank and Obamacare are the two archetypes.

And so we have Congress in passing Obamacare putting in provisions designed to bludgeon the states into participating by making spending subsidies available and imposing taxes for non-compliance only in those states that cooperated by setting up their own insurance exchanges.  That was followed by 36 of the 50 declining to do it and daring the federal government to step in.  And in the next move the IRS declared by regulation that it could impose the taxes and disburse the spending on its own as a supposed "interpretation" of the statute.   This is now taxing and spending amounting to some hundreds of billions of dollars over short time periods, trillions if you go a little longer. 

In saying that the provisions of Obamacare were "designed to bludgeon the states into participating," I am mindful of the proposition that attributing an "intent" to Congress is a perilous thing, and I am also mindful of the limitations of statutory history.  On the other hand, I was around for this one.  Obamacare was the number one subject of the public discourse in this country in the year plus period up to its passage, and right in the middle of that discussion was the question of how Congress would attempt to make reluctant red states go along.  Newspapers, opinion journals and web sites were filled with discussions of this topic.  Surely, it is not possible for anyone alive then to claim to have forgotten.

Reading the dissent of Judge Edwards in the D.C. Circuit, I would summarize his position as "the IRS can do whatever it takes to make this statute work." 

Appellants’ proffered construction of the statute would
permit States to exempt many people from the individual
mandate and thereby thwart a central element of the ACA. As
Appellants’ amici candidly acknowledge, if subsidies are
unavailable to taxpayers in States with HHS-created
Exchanges, “the structure of the ACA will crumble.” Scott
Pruitt, ObamaCare’s Next Legal Challenge, WALL ST. J.,
Dec. 1, 2013. It is inconceivable that Congress intended to
give States the power to cause the ACA to “crumble.”

So according to Judge Edwards, the IRS can impose hundreds of billions of dollars of taxing and spending on the people when those things were never voted by the Congress, on the ground that the IRS has broad discretion to implement its view of how to make the statute work better.  If this is right, then I guess Congress could have just passed a statute saying "Congress hereby declares that there shall be affordable health insurance available to all; IRS to implement."  And with that, the IRS can impose whatever taxes and spending it wants without further authorization.

Here's the most discouraging thing of all:  It appears that how a judge regards the constitutionality of these IRS actions is a completely partisan thing.  In the two Obamacare decisions that came out yesterday (D.C. Circuit here and 4th Circuit here), the four judges appointed by Democratic presidents all voted to uphold the IRS actions, while the two judges appointed by Republicans (both in the D.C. Circuit) held that the IRS had exceeded its authority.  Will that perfect partisan divide continue?

Again, it's two visions of how the world should work.  If your vision is that the world should be run by unelected, neutral "experts" who can impose perfect fairness in human interactions by writing enough regulations, then I guess you think what the IRS did is just fine.  If you think that the functioning of our republic through the mechanisms spelled out in the constitution has great importance, then you will have a very different view.