I'm not going to rant on for several pages, though I certainly could. Just several quick points. (Some of the terms may require reference to my technical page on guns.)
Don't get me wrong, the police do the best they can, but they can't be everywhere. There's a name for places where they can -- a police state! That brings us to, though crime seems to be the anti-gunners' main point:
Even omitting the other writings, the Second Amendment does not even mention "sporting purposes". It is absurd to infer that that is what was meant, in a document specifically devoted to protecting the rights of the people against governmental tyranny.
Translated into clear modern English, the Second Amendment would read:
Since smoothly functioning militias are necessary to the security of a free nation, the right of all citizens to own and carry weapons shall not be limited.
(The connection from armed populace to militia is that a militiaman is expected to supply his own weaponry, and already be proficient with it, or at least with arms in general. This, of course, is far easier if the populace is explicitly allowed (or encouraged!) to be armed, and utterly impossible if the populace is disarmed!)
For more political information on guns, see:
Here are more things I've written on the political issue of guns: