A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

Here's one I have a beef with SOME conservatives about. Nowhere in that does it say the government can't outlaw certain types of weapons. It merely says that they can't keep us from owning weapons in general. Do I believe that means the government can outlaw ownership of everything but revolvers and lever rod rifles? No of course not; but where the line should be drawn is a separate issue from "can the government in fact draw a line?"

On a related note, I also don't believe the 2nd means the government can't restrict where we can carry guns. In the time frame the COTUS was written Bear Arms meant own weapons, and in fact in many colonial cities of the era it was illegal to carry a gun in town. That's why duels were legal but always took place outside city limits. It wasn't until the wild west where we seen gunfights happening on main street, and that was actually much less common than the movies would have you believe.