Lean Left has a thorough discussion of the issues here. The thrust of Lean Left's take is that there is more to the basis of these medical futility cases than can be adequately determined through emotion and the medical awareness of families and supporters for any particular case.
Mark Kleiman accedes these points but goes on to mention that:
Thanks to a reader, I've finally managed to make sense out a distinction that might be made by those who are outraged about Schiavo but silent about the Texas cases. They can't breathe without assistance; she is able to breathe on her own, but can't swallow and therefore needs to be fed through a tube.
Some of the major religious traditions regard assisted breathing, but not tube-feeding, as an "extraordinary" measure, so that taking away her feeding tube counts as killing while taking away Sun Hudson's breathing tube didn't.
That distinction seems utterly arbitrary to me. In particular, it doesn't distinguish between a "terminal" and a "non-terminal" case in any meaningful sense; in each instance, it might be possible to maintain the heartbeat and brainstem indefinitely.
Still, it might seem valid to someone else, who could then have at least a subjective good-faith reason to want to keep Schiavo alive while not minding the removal of life support from Hudson and Nikolouzos. (I'd still argue that awareness is morally relevant to the question of ending care, while the specific function that needs assistance and the life expectancy of the patient are irrelevant, but your mileage may vary.)
Nonetheless, if the distinction among the cases is so fine-grained, it's hard to credit the sincerity of people who throw around terms such as "murder" and "Dachau" when talking about Schiavo but make no objection to the Texas law, especially since the Texas law specifically lists "artificial nutrition and hydration" as among the services that can be discontinued.
Moreover, the law allows for (even if in the Hudson and and Nikolouzos cases it did not actually involve) the termination of life-sustaining treatment for patients with "irreversible" conditions (i.e., conditions from which they will not recover and which leave them unable to care for themselves) even if their higher brain functions are completely normal. Indeed, the law contemplates that a fully competent patient may be served by his health-care provider with a 10-day notice to find another provider or have his plug pulled; it even provides that the patient has the right to attend the committee meeting at which his fate is to be decided. (Sec. 166.046) And the law provides no substantive guidance other than the provider's decision that the requested life-sustaining care would be "inappropriate."
So, if I read the Texas law correctly, it would allow for Terri Schiavo's feedling tube to be disconnected if her health care provider so decided, and if her family couldn't find another provider willing to take the case, even if her higher brain functions were entirely normal (rather than, as appears to be the case, entirely absent), even if she were awake and asking to be allowed to live.
So, I repeat, where's the outrage? If you think Terri Schiavo is being murdered, you think that George W. Bush signed a bill allowing murder in 1999, and that bill is still on the books. Perhaps Mr. Bush flew to the wrong capital on Sunday; some people in Austin seem to need instruction about the "presumption in favor of life."
Last night's cable TV "news" coverage included a Keith Olberman interview with the political reporter from the Dallas Morning News who inexplicably argued that Bush's position was "consistent" when he both agree to the 1999 Texas legislation allowing hospitals to pull the plug over patient's families' objections but at the same time rushing back to DC to sign into law the Terri Schiavo bill in order to err on the side of "life". Unfortunately, Olberman, reliable as he usually is, let the Dallas reporter off the hook by not challenging his conclusion.
Surprisingly, of all people, Larry King referred to the Texas statutes on his show and in interviewing Michael Schiavo, indicated that one of the reasons hospitals could use to deny continued treatment was the "ability to pay".
Although I lean towards Kleiman's view here, you should read the analysis from Lean Left as well.
Post Script: And, oh yeah, Bush's press guy, Mark McClellan, yesterday, LIED about what the Texas law did. But you probably knew that already.