When the federal government banned alcohol in 1919, why did they use a constitutional amendment instead of a law?

Because nothing in the Constitution gave the government authority to ban alcohol. The same is true for firearms. Infringing on the #RTKBA requires a Const. Amdt.

6:57 AM · Jun 2, 2022·Twitter for iPhone

https://twitter.com/RepThomasMassie/status/1532315424196550656