Prohibition is over (see 21st Amendment), so the “A” should go. Tobacco is a legal substance, so the “T” should go. Firearms ownership is Constitutionally protected (see 2nd Amendment), so the “F” should go. That leaves the “E” for explosives. We do not need an entire federal agency just for explosives. The Bureau of Alcohol, Tobacco, Firearms, and Explosives should be abolished.
“E” is covered by the 2nd Amendment as well.