Well, they've passed it, but is it Constitutional? Can the Commerce Clause of the US Constitution be used to FORCE someone to participate in commerce under the penalty of taxes or jail time? It all depends on who you're asking. Liberals see no problem with government expansion into this facet of their lives. Conservatives have a huge problem with it, and want nothing to do with being forced to buy anything.
Disingenously, Dems are claiming that this is like having to purchase car insurance. No one is forced to buy a car. Likewise, no one is forced to drive. You can own a car WITHOUT having a driver's license, and simply never drive it. You can have a driver's license and never own a car. It is the ACT of driving the car on the road which requires insurance, and that happens to be a STATE requirement in order to protect anyone you might hit with your car while driving. So, being forced to purchase insurance, for no other reason other than being alive in the United States today is like being required (by a State) to have valid insurance in the event you wreck and cause serious harm to someone else's life or property. Um, that doesn't compute, guys. Try again.