...I find myself wondering how such a stupid idea ever gained sufficient public support to become law -- and not just a statute, but an amendment to The Constitution...
Even more remarkable when you consider the extent to which the federal government (and, likely, state and local governments, too) was reliant on excise-tax revenues, the bulk of which came from spirits.
Prior to the enactment of the income tax in 1914, fully 90 percent of government revenue came from excise taxes -- most commonly (as is the case today) levied against alcohol and cigarettes. I recently read (but have not yet again found the reference) that alcohol/spirits accounted for nearly 75% of that revenue, but, in any case, it is widely reported that those taxes were still nearly half of federal income at the onset of Prohibition in 1919.
It's certainly arguable that the loss of excise tax revenues at least hindered the governmental response to the stock market crash and the Depression which began a decade later, if not that it was an actual cause of it.
Furthermore, it seems ironic that it was economic necessity -- the need for further revenue -- as well as the utter failure of Volstead to actually 'prohibit' anything, that drove repeal, not a reversal in the attitudes of the temperence reformists.