I've read two very good analyses tonight.  

The first dissects the Florida law and shows that the stand your ground law doesn't apply and even if it did that there was still probable cause to arrest Mr. Zimmerman.  It makes more carefully and thoroughly some of the points regarding self-defense, being the aggressor, and justifiable use of deadly force I made in my previous post on the subject.

This second article is an opinion column (which directed me to the first analysis) which criticizes the social flaws that led to this situation, including the lobbying efforts of the NRA, which were pormulgated by the "law and order crowd" but have led to more violence.  Here is the conclusion:

And that's really what this case is all about - and what the NRA and ALEC's rewriting of gun laws is all about as well. On one side, there is the long-standing common law requirement of acting in a reasonable manner, and standing in judgment before one's peers. On the other side - by reshaping the letter, the spirit, and the interpretation of the law - lies vigilante "justice" - the individual or mob as judge, jury and executioner, all in one and all at once. Whatever they think, want, feel or do in the moment is by definition "reasonable". Questioning them in the slightest is not. It could get you killed.

As previous privileges drain away over time, and the letter of the law actually comes to protect those who formerly had few, if any, rights that were actually protected, those whose privileges have been eroded want the old order back, and vigilantism is one way to get it.