Absolutely so, Jessica.
@Drago: I don't think so. In fact, I don't think there really can be an opposite of ratio dedidendi, but if there is, you might be right, using the same line of reasoning that says that the opposite of love isn't hate, but indifference.
And msturner, didn't we just know that someone would find a way to bring manufacturing under the interstate commerce umbrella? But your point is excellent; obiter dicta can't be passed over as irrelevant.