'The Second amendment is not about hunting deer or keeping a pistol in your nightstand. It is not about protecting oneself against common criminals. It is about preventing tyranny. The Founders knew that unarmed citizens would never be able to overthrow a tyrannical government as they did. They envisioned government as a servant, not a master, of the American people. The muskets they used against the British Army were the assault rifles of the time. It is practical, rather than alarmist, to understand that unarmed citizens cannot be secure in their freedoms. It's convenient for gun banners to dismiss this argument by saying "That could never happen here, this is America"- but history shows that only vigilant people can keep government under control. By banning certain weapons today, we may plant the seeds for tyranny to flourish ten, thirty, or fifty years from now. Tortured interpretations of the Second amendment cannot change the fact that both the letter of the amendment itself and the legislative history conclusively show that the Founders intended ordinary citizens to be armed. The notion that the Second amendment confers rights only upon organized state-run militias is preposterous; the amendment is meaningless unless it protects the gun rights of individuals.'
-Dr. Ron Paul
I slightly disagree with Ron Paul on the idea that it's 'not about keeping a pistol in your nightstand', because I believe that self-defense is a basic human right, and having the tools necessary to defend yourself and others should be allowed, regardless of what the constitution says. It doesn't matter what the text of the Second Amendment says. You have a right to live, so by extension, you have a right to defend yourself, and by extension of that, you have a right to be armed for that purpose. As I heard someone say recently "You can't carry a cop in your pocket".
Thomas Jefferson said "The constitutions of most of our States assert that all power is inherent in the people; ...that it is their right and duty to be at all times armed."