In this whole thought experiment the answer to that question just isn't that easy to come up with. Now I know if you don't like the healthcare bill you already have decided that it is not constitutional. This is the knee-jerk reaction of partisans who respond to the political success of the hated other wing. I heard tons of similar arguments during the Bush years. Idiot Seattle progressives yacked all the time about how Bush was crapping on the constitution, and often they were right but they really didn't understand why.
Whether you agree or not with the bill, a challenge on the constitutionality of the law will need to be brought by someone who claims they have been damaged directly by it. They must have a case. This will not be possible for some time until the law has been enacted for awhile. The threats of lawsuits by a few State Attorney Generals is merely symbolic and probably a ploy for free publicity as they gear up a future run for governor.
The type of case will need to come from shareholders of an insurance company that may claim that they were ruined directly by the law. This will hardly be possible as the Federal Government can protect any insurance company from failure with an executive order. It may be brought by a doctor who claims that his disassociation from a 3rd party payor is infringed. Most certainly this is a reasonable claim, but will it be taken seriously by court that thinks the meaning of laws are as elusive as holding a water weiny? Once the law is in place and someone can be damaged by it...then and only then can someone bring a case on the slow journey through the federal courts on its way to the Supreme Court. The Court must consider the claim of someone damaged as they view any enacted law as the will of the people...whether you like it now or not.
As I've predicted over and over that President Obama will be re-elected, it is quite possible that in the year 2014 the Supreme Court will have that quaint living and breathing view of the law of the land. The kind of view that will make amendments obsolete because its words will evolve into the useful meaning of the day rather than original intent.
And by the way...this bill is not socialism. Not even close. This bill is just more good ol' fashioned Corporatism where the winners and losers will be chosen in DC. It's significant but hardly radical. Not nearly as radical as say...attacking a sovereign nation who never attacked you...just sayin'.
Oh, and a message to you angry GOP morons out there. Maybe you would've been more believable in this whole argument had you whined and protested like this during the Medicare prescription plan a few years ago that so many of you voted for. You expanded the state by throwing bill after bill at a president who didn't veto any proposed legislation until well into his second term. It's so frustrating to watch someone else expand the state while you have to just sit back and watch isn't it?
As for me, this bill is not compatible with The Constitution I've read. It is not compatible with that of a free society...but neither was the former system. I have a replica of the constitution on the wall in my downstairs bathroom. I joke constantly that I can tell what political party my friends belong to when they use that bathroom. The Democrats look at it and ask what it is and the Republicans try to use it for toilet paper.
So anyway, get used to it. It's the law and will be for a long time.