Here's a thought experiment. Imagine that I tell you 100 things that you may not do tomorrow. For example, you cannot run on a treadmill, eat broccoli, buy a car, and 97 other things. While your liberty would be restricted, there would still be an infinite number of things you may still do.
Now suppose I tell you 100 things that you must do tomorrow. You must run on a treadmill, eat broccoli, buy a car, and 97 other things. These 100 mandates could potentially occupy all your time and consume all your financial resources.Be sure to read the whole thing.
You can see why economic mandates such as the individual mandate in Obamacare are so much more onerous than either economic regulations or prohibitions, and why so dangerous an unwritten congressional power should not be implied.