The ban of alcohol in the United States was actually a triumph of democracy over moneyed interests and the government. At the time, alcohol manufacturers had tremendous political power, and excise taxes on alcohol made up about 1/3 of federal revenue. What made prohibition pass legislatures around the country was a concerted effort by devoted constituencies: Christians and women. Indeed, one of the primary drivers of women's suffrage in the United States was prohibition--alcohol was seen by many leading suffragists as being at the root of social ills like domestic violence.
One of the most interesting charts I've seen with regards to the modern drug war is this one: http://www.people-press.org/2013/04/04/majority-now-supports.... My recollection of childhood, of school assemblies with adults shrieking "Just Say No!" wasn't wrong. When I was a kid in the early 1990's, the popular position was in favor of keeping marijuana illegal by an almost 80-20 margin. This is a country that couldn't agree on anything (in 1992, they voted for Bill Clinton over George Bush by a 43-37 margin), yet they almost all agreed that marijuana (we're not even talking about harder drugs) should be illegal.