So that applies in every situation? Every state? Hawaii and Florida support that kind of action, what if you live elsewhere? What constitutes a situation where deadly force is necessary? I think that we all can agree that if someone is trying to shoot you then you're justified in shooting them, but what if you have a gun and they have a knife? A bat? Just their fists? Who's to say that you're not overreacting to the situation and are making it out to be a bigger threat than what it is? What I'm trying to say is that this needs to be considered in a case by case scenereo, there isn't a blanket rule that will apply to every situation everytime.
All but two states allow CCW. I hope this map shows up.
http://therealrevo.com/blog/wp-content/uploads/2009/07/ccw_map_2006.jpg
There are videos on youtube that I can't link here. Go to youtube and search this: "murder or self defense, you decide". That man was found not guilty. The man shot had no weapon. It's your basic right to defend yourself against what you believe to be "great bodily harm". The main difference is "stand your ground" states and "duty to retreat" states. I live in a duty to retreat state. This means I have the duty to retreat (if outside my home or business) if completely safe to do so before using deadly force. In Zimmermans case, and the video you are about to look up, They have the right to meet force with force... stand their ground. Thats how the laws are written, because if you try to look at it on a case by case basis, you can throw all laws out the window. There wouldn't be any base guidelines to follow. Chaos would ensue, and the system would be greatly abused by both sides. I can't say which I find more preferable, because duty to retreat is a great idea, but the right to stop someone who is charging you seems like a decision you should have the right to make, too. If the scenario in the video happened in my state, he would definitely be found guilty of manslaughter. Although, it is arguable that he was retreating when he blew the stop sign to flee the attacker.
Edit: I know it is an old map, but I don't think it has changed too much.