Akhil Reed Amar is making sense:
I start with the Constitution here. It’s the power to regulate interstate commerce. Is this a regulation? Yes. It’s just a regulation like regulating a well-regulated militia with a mandate. Is this interstate? Yes. And I’ve given you reasons why. Third, is it commercial? Yes, it’s purely about who is paying.
EK: In terms of liberty, I think what Barnett and other opponents of the mandate are arguing is that this is a slippery slope. First you’re saying I have to buy health insurance. Then you’re saying I have to eat broccoli.
ARA: The most important limit, the one we fought the Revolutionary War for, is that the people doing this to you are the people you elect. That’s the main check. The broccoli argument is like something they said when we were debating the income tax: If they can tax me, they can tax me at 100 percent! And yes, they can. But they won’t. Because you could vote them out of office. They have the power to do all sorts of ridiculous things that they won’t do because you’d vote them out of office. If they can prevent me from growing pot, can they prevent me from buying broccoli? Perhaps, but why would they if they want to be reelected? So if you ask me what the limits are, I’d say read McCulloch vs. Maryland. And reread it. And keep reading it till you understand it. The Constitution is a practical document,. it’s designed to work. And the powers are designed to be flexible in order to achieve the aims of the document.
On their economic ignorance, see Krugman.