@ZGoon: It is pretty ignorant, not to mention rude, to speak this way about another country's culture that you admit to not understanding (which is odd since you're in Canada and not half a world away).
The answer is that more traditional freedom-focused Americans prefer said freedom to government imposed "safety." Also, the founding fathers of the United States were not perfect people but their ideas and the logic behind them were the height of political and social genius. This is why the Constitution, while abused by authoritarian politicans, has not been overtly thrown out by them...the people still love it you see.
People forget that one of the smartest parts of the Constitution's design is the ability to change it to fit the changing needs and wants of society. So Americans could very well have the Second Amendment repealed, but, again, at least half the country is more traditionally minded and we much prefer the freedom to own what we want and a defense against tyranny.
Sorry, I stopped listening after you said people who thought it was okay to own another human being were "the height of political and social genius".