Their initial purpose was to enforce/gather the excise taxes on liquor and tobacco, and later included the transfer tax on class III weapons as well.
IIRC, Lloyd Bentsen was the one who essentially declared the street sweeper and other firearms to be "destructive devices" under the ATF regs during the Clinton Administration, and he was Secretary of the Treasury then.
I agree that the NFA of '34, GCA of 68 and a host of other infringements ought to be repealed, but the best opportunity we have had for such in decades was wasted by the former majority holders in both houses. Pity.
Ga Democrat (former senator) Zell Miller is a lot more conservative than any of the current leading Republican presidential hopefuls. Can you imagine what will happen with our gun rights if Guiliani, Romney, Mccain, or Clinton becomes president. There isn't a f@rt in a hurricane's worth of difference among them in this regard