Using the Military's definition of an Assault Weapon: "A SELECTIVE FIRE (Semi Auto or Full Auto) weapon that fires a reduced power cartridge ..."
1) None of the "Assault Weapons" on Mr. Clinton's list were a true Assault weapon.
2) All were a semi auto only civilian version of the military rifle.
3) Those that fired a full power cartridge like the .30-06 or 7.62 NATO (.308 Winchester) would not be an assault weapon, even if they were selective fire.
4) Only three of the guns on the ban list had ever been used in a crime.
5) The guns were banned because they are black and look "mean."
On a related note, there was one benefit of the ban. The full auto/selective fire versions of the banned semi auto only guns were NOT banned, AND, the Federal Excise Tax for class 3 Arms was lowered from $500.00 to $25.00
So it became easier - and cheaper -to acquire the full auto/selective fire versions
The Supreme Court ruled back in the late 60's or early/mid 70's (soon after the Gun Control Act of 1968 was passed) that excessive taxation on a product such as ammunition is unconstitutional.
As for the 2nd, as others have pointed out, makes no limits on what kinds of arms can be born by the people, but I think WMD's are a bit over the top for Joe 12 pack especially in this day and age.