Even so, Obama's comments have attracted criticism. Last fall, former Republican presidential candidate Mitt Romney said that "it's just not a good idea for people running for president of the United States who potentially could be the role model for a lot of people to talk about their personal failings while they were kids because it opens the doorway to other kids thinking, 'Well, I can do that too and become president of the United States.'"
The thing is, that happens to be demonstrably true. And until politicians admit that smoking marijuana, something at least half of American adults born after World War II have done, is not a harbinger of ruin but a generally harmless rite of passage, they will not be able to have an honest discussion about drug policy.
Obama has gone further than most. He has acknowledged his own pot smoking, and in 2004 he said "we need to decriminalize our marijuana laws," which in the United States usually means people are not subject to arrest for possessing small quantities of the drug.
What Obama has not done is connect the policy of not treating pot smokers as criminals (a position from which his campaign recently seemed to retreat) with his own experience as a pot smoker. Obama would not be better off today if he had been arrested for marijuana possession in high school or college, and there's no reason to think that experience would improve the life prospects of potential presidents who today are sneaking a puff here and there.