"The limit is the Constitution."Akhil Reed Amar, from Ezra Klein's Wonkblog
Amar, a Yale law professor, goes on to say: "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."