If those police officers and sheriff's deputies had even a shred of decency in their character, they should turn in their badges and guns rather than be the guardians of the Terri Schiavo death chamber.
Most police officers swear an oath like this or very similar to this.
"I,__________, do solemnly swear, that I will support and defend the Constitution of the United States, and the Constitution of the State of _______ against all enemies, foreign and domestic; that I will bear true faith and allegiance, to the Constitution of the State Of _______; that I take this obligation freely, without any mental reservations or purpose of evasion; and that I will well and faithfully discharge the duties, of the office of Police Officer of the City of ______, acting to the best of my ability."
Nowhere does it state "except for laws I don't believe in, or if I feel like it."
Could I have handcuffed those kids? No.
But a LEO isn't supposed to choose (hypothetically) which law to enforce nor do they get to pick where their post is. Unfortunately, it is rule of law that put them there. It is not their choice as to what the law is.
Don't blame them, blame the people who made the law....better yet, blame the people who elected/appointed/confirmed the lawmakers/interpretors.