Let Us Carry!

Looks like there has been another college shooting, this time at the University of Alabama.

When will we learn that gun free zones are shooting galleries for bad guys (and apparently in this case gals)? How many students, soldiers, patients, etc. must die before we grow up, follow our own Constitution, and allow* people to carry everywhere and anywhere?

*I'm actually starting to wonder if the Constitution MANDATES that people of militia age carry firearms. Several months ago I sent the following to a (liberal) second amendment scholar who shall remain nameless. He hasn't responded yet so I don't think he ever plans on doing so:

If a well regulated militia is necessary to the security of a free state, why do we no longer have militias? I don't mean that in a quaint way. I'm thinking that we've returned to a state of affairs analogous to that faced by the founding generation, to wit one of "terrorists" (whether they are called Islamo-fascists, Indians, domestic extremists, or whatever) that can strike virtually anywhere, anytime. In this view, the return of a similar Zeitgeist allows for the clarification of the muddled discussions of the last 180-ish years.

So shouldn't someone sue to enforce the Constitution and the original intent of the Founders? Shouldn't the federal government force state governments to pass legislation mandating that all able-bodied adults (perhaps exempting conscientious observers, violent felons, etc.) fulfill their civic duty and carry a firearm with them (perhaps at all times) in order to protect the community from attack? Isn't it clear that nobody, not even military personnel on their own bases, can be protected by police forces for the simple reason that the police can't be everywhere at once and attackers have very clear incentives to attack where police protection is lowest? Do you see where I am going with this? The line between self- and community- defense is not clear cut but rather bleeds (forgive the pun) seamlessly from protection from a mugging through full scale invasion, with the biggest threat at present small scale attacks by one or a few people on groups ranging from a dozen or so to a hundred or so. Whatever the rationale (individual, community, civic duty) for the 2A, "the right of the people to keep and bear arms, shall not be infringed" yet it has been, in particularly egregious fashion from the standpoint of the communal and civic duty interpretations! What have I missed here? Please enlighten me when you have the time.