The main thing, in my opinion, that started this whole deal, that's rather recent, the shooting at that elementary school at Sandy Hook. The main point here is that guns don't kill people, people kill people. 
Of course, this event was a terrible, horrible thing. But a lot of this type of conversation was sparked. Yes, once wrong move with a gun can injure, possible kill someone, but they do keep a lot of people safe. And if having a gun makes someone feel more comfortable, then that should be okay, until they show that there's a valid, actual reason to confiscate it. There's a reason why the Bill of Rights includes this. There was a reason then and there's a reason now.
Not every person in this world is going to misuse a gun. Not everyone is a criminal. In fact, the majority are perfectly sane and reliable.