I watched the house vote on TV and it was very close. As I recall the speaker kept the issue open until he had enough votes. Lots of strong arm tactics to get some members to change their votes to get it passed. I believe the AWB passed by only one vote, gut I can't swear to it.
Like all gun control propaganda there was a ton of down right lies and inuendos flying about. I don't think it would have passed without the sunset clause. That was a good amendment.
Since it had no affect on crime stats at all, I think history gives us a good argument against another ban. After all we already tried that once, sort of like alcohol prohibition.
Cogito, ergo armatum sum