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?
That's a very good question, and there is actually a clear, rational answer to it. The difference betweem the two is the cause of death.
If someone sustains catastrophic injuries in a car accident and is removed from a ventilator, then his death has been caused by his catastrophic injuries. In other words, the fact that the body is unable to sustain itself without the aid of these machines is an indication that death is a clear consequence of the injuries. Keep in mind that I am talking here about someone whose long-term prognosis is not good . . . my statement would not apply to a car accident victim who is on a ventilator on a temporary basis while undergoing surgery that has a reasonable chance of successfully treating the injuries sustained in the accident.
If this person does not require a respirator but needs a feeding tube to stay alive, then removing the feeding tube changes the manner of his death -- and his death is caused by starvation, not by his injuries. In other words, starving a bedridden patient to death is no different than shooting him, because the subsequent action replaces the initial injury as the "proximate" cause of death.