From The Wikipedia Enclyclopedia:
The proponents of Prohibition had believed that banning alcoholic beverages would reduce or even eliminate many social problems, particularly drunkenness, crime, mental illness, and poverty. Journalist H.L. Mencken asserted in 1925 that respect for law diminished rather than increased during Prohibition, and drunkenness, crime, insanity, and resentment towards the federal government had all increased.Some supporters of Prohibition, such as Rev. Charles Stelzle in his 1918 book Why Prohibition!, also believed that Prohibition would eventually lead to reductions in taxes, since drinking "produced half the business" for institutions supported by tax dollars such as courts, jails, hospitals, almshouses, and insane asylums.
In reality, however, alcohol consumption and the incidence of alcohol-related domestic violence were decreasing before the 18th Amendment was passed. Furthermore, reformers "were dismayed to find that child neglect and violence against children actually increased during the Prohibition era."
During Prohibition, people continued to produce and drink alcohol, and bootlegging helped foster a massive industry completely under the control of organized crime. Drinking in speakeasies became increasingly fashionable, and many mothers worried about the allure that alcohol and other illegal activities associated with bootlegging would have over their children.
Prohibitionists argued that Prohibition would be more effective if enforcement were increased. However, increased efforts to enforce Prohibition simply resulted in the government spending more money, rather than less. The economic cost of Prohibition became especially pronounced during the Great Depression. According to Association Against the Prohibition Amendment (AAPA) and Women's Organization for National Prohibition Reform (WONPR) literature, an estimated $861 million dollars was lost in federal tax revenue from untaxed liquor; $40 million dollars was spent annually on Prohibition enforcement.
The AAPA also released a pamphlet claiming that $11,000,000,000 was lost in federal liquor-tax revenue and $310,000,000 was spent on Prohibition enforcement from 1920 to 1931. This lack of potential funding during a period of economic strife became a crucial part of the campaign for repeal.