21st Amendment wouldn't do the trick. The entire point of the 18th Amendment was because people had a much more limited view of what the Federal Government could do in 1921 and thought it needed special permission to ban alcohol. 21st Amendment just restored pre-18th Amendment status quo rather than affirmatively asserting a right to sell booze. It'd be far easier legally to ban it today.
It'd be impossible politically.
Very problematic that something clearly requiring a Constitutional amendment 100 years ago is viewed as not requiring a Constitutional amendment now despite no relevant change to the Constitution. Gonzalez v Raich was an abominable opinion and the wholesale abandonment of Constitutional fidelity now is pathetic as we are seeing with the idiots in Virginia pushing the clearly invalid ERA on the grounds of "well the constitution should let us do this even though it doesn't so we are just gonna do it anyway and demand society just accept our overreach". The federalist papers were clear that Agriculture, mining, and manufacturing are not interstate commerce and now we have nuts insisting that choosing not to buy insurance or carrying a gun near a school or hitting women are "commerce" on account of otherwise we couldn't have these big government programs. Terrible argument. Mere possession of anything should never, ever be considered "commerce". Federal drug laws are despicable.
