As to this case, this doesn't mean anything.
Either there is enough evidence to charge him, or there isn't.
I doubt they would be able to find jurors to hear the case that hasn't read all the media accounts, ie unbiased.
Even if Florida can't charge him, Federal authorities can, if there is evidence he broke federal law.
I personally believe this guy will face street justice if he is not charged. Then he will have been tried, sentenced, and executed via the court of public opinion.
Possibly his least crime? defending himself from an attacker he followed for being suspicious. His worst crime? Manslaughter.
But who cares about the facts when the racist card is played.