designated party police running around with alcohol hydrometers making sure it's not above 6%. What constitutes a "party"? Where 2 or more are gathered? Do we designate it as a single geographic location, lot, house? What if they drink hard alcohol before the "party" then show up?

They will have to create a series of regulations akin to the law of moses to make this doable. Much simpler to just flat out ban alcohol, but obviously that's unrealistic and outdated.