I’ll admit that I wasn’t terribly surprised when the state bowed to political pressure and pressed charges against George Zimmerman. It didn’t matter that the investigators had said that there wasn’t enough evidence to go to trial; when it gets to the point that the President of the United States weighs in, albeit tangentially and grotesquely irresponsibly, you’re obliged to at least go through the motions.
Where I was surprised was that they decided to go for a murder charge.
The original investigator had said that he wasn’t entirely comfortable with Zimmerman’s statement, and that some more digging might turn up enough evidence for a manslaughter charge. He would ultimately change his mind, but that initial recommendation should have clued the state in on what they might actually hope to accomplish by the trial.
And that is one of the important questions: What does the state hope to accomplish by this trial?
If it’s the deterrence of any would-be vigilantes to hide behind the Stand Your Ground law (which, incidentally, is quite possibly irrelevant in this case), then it’s likely a manslaughter charge would have sufficed, much as it would have if simple punishment of Zimmerman were the intent. Manslaughter with a firearm in Florida carries a sentence of up to 30 years in prison, after all.
The state’s choice to go for a murder conviction points towards something else.
It indicates that they don’t just want to make an example of Zimmerman in the classical sense, a “what not to do” guideline for neighborhood watchmen and concealed carry permit holders. They want to make him an example, yes, but not because of what he did, but because of what they were perceived to not have done.
Doing so requires them to not only prove that what Zimmerman did was wrong, but that everything his detractors have said about him was right.
They don’t just need to make an example of him, they need to demonize him. To prove that they’re not just tough on crime but tough on racism, and to do so they have to prove that not only was it a crime, but it was a heinous crime, committed by a hateful monster.
I expect that in the end all it will prove is that they’re inept.
Proving a manslaughter charge would have been difficult enough. The second degree murder charge that they chose to levy requires them to prove not only what happened, but what Zimmerman was thinking at the time. To prove that his actions weren’t negligent, but malevolent.
And that will be extraordinarily difficult. It’s possible to cast doubt on his motives, to be sure. But to prove beyond a reasonable doubt that he killed Trayvon Martin out of rage and hatred?
I don’t give much for their chances.
Shambling Towards Bethlehem 
Agreed, they set themselves up for failure for political reasons not jurisdictional reasons. To perform in good faith for this political decision, they have to pull out all the stops and hope the defense slips up. They filed the charges after the window closed on trumped up reasons. There is not enough evidence to support this, just politics driving injustice.