On the relative dangers of marijuana and alcohol, the public is now in line with what medical researchers have been saying for years. A 2010 study in the journal Lancet, for instance, graded common drugs on sixteen criteria relating to how harmful the drugs were to users, and how harmful they were to society overall. On both measures - harm to self and harm to users - marijuana scored significantly lower than alcohol.
In fact, alcohol was the most dangerous of all the drugs studied, vastly more dangerous than other drugs in terms of harm to society, and behind only meth, crack and heroin when it came to harm to users.
Other topline findings from the Pew survey: significant majorities approve of marijuana legalization, say that mandatory minimum sentences for non-violent drug crimes are a bad idea, and want the federal government to focus more on providing treatment to drug users, rather than prosecuting them.
In short, it's hard to think of another arena in which federal policy is more at odds with public opinion and scientific consensus. The Pew survey suggests that in the upcoming national elections in 2014 and 2016, there's a real opportunity for candidates to distinguish themselves by taking up these issues.