via the Huffington Post:
As both a U.S. Attorney and Member of Congress, I defended drug prohibition. But it has become increasingly clear to me, after much study, that our current strategy has not worked and will not work. The other candidates for president prefer not to address this issue, but ignoring the failure of existing policy exhibits both a poverty of thought and an absence of political courage. The federal government must turn the decision on drug policy back to the states and the citizens themselves.
My change in perspective might shock some people, but leadership requires a willingness to assess evidence and recognize when a strategy is not working. We are paying far too high a price for today's failed policy to continue it simply because it has always been done that way.
It is obvious that, like Prohibition's effort to eradicate alcohol usage, drug prohibition has not succeeded. Despite enormous law enforcement efforts -- including the dedicated service of many thousands of professional men and women -- the government has not halted drug use. Indeed, the problem is worse today than in 1972, when Richard Nixon first coined the phrase "War on Drugs."
Whether we like it or not, tens of millions of Americans have used and will continue to use drugs. Yet in 2005 we spent more than $12 billion on federal drug enforcement efforts. Another $30 billion went to incarcerate non-violent drug offenders.