Distinction without difference

I've seen a lot of commentary over the last few days about the so-called "individual mandate" in the Affordable Care Act (ACA) that discusses how the mandate is beyond the power(s) of the U.S. federal government and that the Supreme Court would be right to strike it down. Those same commentaries, however, then concede that the same federal government does have the authority to raise taxes and then use that money to provide health care, a la Social Security.

Two thoughts immediately come to mind:

1. If the commentary, as described above, is correct, why is there such an uproar about the mandate? If the federal government really does have the authority--assuming it does so via the "proper" means--to force health care on every person within its jurisdiction, wouldn't it be far less injurious to individual liberty to allow people to choose from which provider they will get their insurance and the terms of that insurance? Furthermore, wouldn't it be far more economically efficient if individuals purchased insurance for themselves, saving the cost--both monetary and bureaucratic--of the government having to hire more IRS agents to collect the money and more functionaries to manage it?


2. Isn't the real problem that the U.S. Constitution is all but worthless at this point? That is, if the mandate is such an affront to individual liberty, but the constitution allows the government to achieve the same ends via different means, what good is it as a protector of that liberty?