Well there are other factors to look at -

The population of Australia is 22 million while in the US it is 313 million, so it is a lot more likely that someone would snap. It also means that if that one kid in school did die, percentage wise, that is almost equal to the 20 kids that died in Sand Hook ES.

A person with a knife can actually do a lot of harm. In China where guns are banned, they have people snap and kill many people with a knife. For example. the same day as Sandy Hook, a man in china slashed 23 students in an elementary school.

And when it comes to the constitution, well the bill of rights is what we are talking about, it is a set of rights to protect us from a corrupt government. One might say that we have a democratic government so we should just use our power of voting. But no, we live in a representative democracy. It would still be easy for corruption to enter into the government, it already has. Now I don't think Obama is a Nazi, I actually think he is doing a good job, but when you look at most of the senate and house, some bills that are being passed have no reason to be passed unless some company is paying them. Just look at how stupid the right to work act is.

The right to bear arms protects democracy. Look at the Civil War, before you think I am racist, the war was not started because of slavery, if you ask I can explain, but I don't have the character count left. Why do you think there were only two peopled tried for war crimes after the war and the rest were let go back to their homes? It is because it was their right to rebel. Around 50% of the country was upset with Lincoln and the legislators. They felt the federal government was getting to powerful, and no matter who they voted for in the next election they would still have to live under this large government. You also have to remember that the Revolutionary War was only around 80 years before this and they remember what they thought was tyranny from Britain.