Though it's difficult to tell what a liberal means at any given date or time, the term "collective right" is usually used in anti-gun-rights circles to express the notion that the 2nd amendment guarantees no right for you and I to own or carry guns, but only guarantees the right of STATES to form militias. Thus the only way you or I can own a gun, is if we are members of an official state militia.
It's sort of like claiming the 1st amendment doesn't protect your or my right to say what we want, but only protects (say) high schools' and literary societies' right to put on plays, in which actors recite lines. Thus the only way you or I get to say anything, is if we are members of a cast of a play.
Both interpretations (of the 1st and the 2nd amendments) are equally ridiculous. Yet somehow a few people cling to that very belief about the 2nd amendment, though probably none of them believe it about the 1st.
I'm not trying to justify what these people think (if that's what they're doing). I'm just telling you what THEY say the 2nd amendment means.
