1. The Second Amendment
Since we are bringing up the constitution, let's just give the text:
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.I'm not going to bother with whether or not this deals with the individual right to own guns, as the Supreme Court has already weighed in, and thus we know for certain that the second amendment does protect an individuals right to own a gun for self defense.
Thus, to the issue we are discussing - is the second amendment a valid argument against a military-style assault rifle ban? No, laughably no. Congress has the right to reasonable gun restrictions. They can't eliminate one's right to own a gun, but they can do an awful lot of reasonable restricting. The second amendment gives one the right to own a gun, but it does not give one the right to own ANY gun. The second amendment doesn't give one the right to own a nuclear missal and it doesn't give one the right to own a military-style assault rifle - it only gives one the right to own a gun. So stop dragging the second amendment into this, it has nothing to do with it. If military-style assault rifles are banned again, as they were during part of the 90s and 00s before the bill failed to be renewed, one will still have the right to own a gun, and to own an overwhelmingly large number and variety of guns. If the bill is anything like the previous one, it will actually specifically protect citizen's rights to own certain guns (a compromise that helped it pass last time). One will still have their second amendment rights if a ban on military-style assault rifles passes.
2. No Other Uses
The other argument I am tired of hearing is that military-style assault rifles have no other uses but to kill as many people as quickly as possible. If killing as many people as quickly as possible was the sole reason for the existence of these guns, then why would so many people own them?
Some people collect guns (yes, like stamps or coins). Some people just enjoy going to the range to shoot these (honestly, you would be surprised at the number of people who get a kick solely out of owning guns just to shoot them at ranges). For some people guns like these are a hobby. We live in a country where it isn't uncommon for people to have access to enormous material wealth, and their use of that wealth doesn't always relate to some supposed designated purpose of an item.
Debate is typically healthy, and it is nice to hear topics being discussed. People also need to be realistic when they discuss these topics though. It is important that we thoroughly discuss the issues at hand, and seek out the potential unintended consequences. In order to do this however, we can't keep coming back to red herring arguments. The two issues I stated above serve merely to distract from the point being discussed - what steps can be taken to reasonably reduce the gun violence seen in this country.