The Nancy Cruzan case wasn't a state law -- it was a U.S. Supreme Court case in which the "Men in Black Robes" overturned a Missouri law that prohibited the removal of a feeding tube.
When did I say any of that? I said many state laws began after those. I'm well aware of the decisions and their repercussions. And why is a respirator more of an artifical life support than say a feeding tube?