Gun Control Policy in the United States- Reasons to Carry a Weapon?

Ok, I want to preface this question by saying that I am looking for honest answers, and I will try my best not to insult anyone on either side of the coin. Basically, this is what I want to say. Obviously what happened at Sandy Hook Elementary school is an American tragedy, felt and mourned by all. Just like... show more Ok, I want to preface this question by saying that I am looking for honest answers, and I will try my best not to insult anyone on either side of the coin.
Basically, this is what I want to say.
Obviously what happened at Sandy Hook Elementary school is an American tragedy, felt and mourned by all. Just like the shootings at Virginia Tech, and Columbine, the nation remembers the victims as a devastating loss of innocence and potential.
The thing I struggle with understanding is the crazy gun control debate that has been raging since last Friday.
Why would someone be opposed to strengthening the gun control policies in the United States? It seems the only choice is to crack down on the availability of assault weapons in our country. People say that a criminal background check is required to own a gun, but is that all? It only takes one time for someone to snap and charge into a school or business, guns blazing. You might be squeaky clean before that instance, and with the criteria of only a background check, you would be allowed to obtain a firearm. Why not a mental health assessment from a licensed psychiatrist as well? Having someone test you under stressful situations and see your anger reflex, or how you comport yourself. That seems fair. If you're not a psycho prone to flying off the handle, there shouldn't be a problem with taking that additional measure before we just let anyone own a weapon like that.
The second point. Why would anyone need an automatic weapon? Why are they even available to citizens? Handguns are scary enough, considering they are so small and portable. But an automatic weapon? Why on earth would anyone EVER need to fire off 20 rounds in 4 seconds? What could that possibly be used for, if not to massacre people? Hunting? No.
So what's the point? Why are people freaking out over personal liberties being stolen, when our ****** up laws allow lives to be stolen?

I'm not trying to take your guns away. I'm just trying to understand this.
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