Last poker metaphor, I swear!
You got to know when to hold 'em, know when to fold 'em. Know when to walk away, know when to run.
Jeb knew it was time to fold here. He encountered resistance on almost every level, and chose inaction over a potentially dangerous clash between local law enforcement and state agents. There was a risk that the local cops would ignore his direct order, and thus permanently hobble his authority (as it is, there is no such explicit defiance). Of course, there are those who are upset he went as far as he did, and others who are irate that he did not press on. I don't know which is the more politically potent. On the whole, however, I believe the point is moot, as I don't see Jeb pursuing the Presidency.
This whole situation was all around bad, for everyone involved. Unlike others here, I don't really believe this to be a case of judicial tyranny--just really bad law on the books, and an unwillingness on the part of the FL legislature to change it for the better. That, and a bizarre fact pattern featuring a intra-family feud, a sleazy husband, links between the hospice and the judge, etc., etc. They say hard cases make bad law.
No one's power is absolute. It exists only so far as others will obey. Even Alexander the Great was forced to abandon further conquests in India because his army refused to go farther. Sometimes, in order to keep a position of power, a leader must abide with the prevailing sentiment. I'm sorry to say, the prevailing sentiment in this case was to remove Terri's tube.
While much bitterness was born out of this case, there was some good: more folks will draft living wills, and more scrutiny will be paid to overbroad statutes defining feeding tubes as life support, with probable changes. Terri will be remembered for that. I don't see this case as marking the beginning of a nightmarish Eugenics program, nor do I see it as splintering conservatism or the GOP.
If he wasn't going to overrule the obviously-expected Greer response to his press conference, why did he have it? He could have gone in discretely with a DCF agent and had Terri receiving hydration before Greer could react (note that Greer's order at that time forbid Michael from allowing Terri hydration, but did not say DCF couldn't provide hydration over Michael's objections). His behavior there made no sense unless he was more interested in saying he 'tried' than he was in getting results.