I contend that the opinion of prohibitionists is insufficient to establish that an amendment was not needed.
Conservatives should note the following about prohibitionists:
'Progressivism and prohibition were, in his [historian James H. Timberlake's] view, closely related middle-class reform movements seeking to deal with social and economic problems through the use of governmental power. They drew on the same broad base of support and moral idealism, and they proposed similar solutions to society's ills. Examinations of temperance campaigns in such varied states as Texas, Washington, Tennessee, New Mexico, Virginia, California, and Missouri support Timberlake's conclusion that "prohibition was actually written into the Constitution as a progressive reform." [...]
'Far more optimistic than the preceding generation about man's capacity to solve problems and mold a satisfactory world, Progressives believed that their goals could be reached by creating the proper laws and institutions. Whether the particular task into which they plunged was raising the quality of life for the urban working class, conserving natural resources, establishing professional societies and standards, improving governmental morality, democracy, and services, or controlling business practices, Progressives repeatedly displayed their unshakable confidence that legal and bureaucratic instruments could be found which would permanently uplift that aspect of their environment.' "They believed," as Ralph H. Gabriel put it, "that man, by using his intellect can re-make society, that he can become the creator of a world organized for man's advantage."'