Speaking at the Western Conservative Summit in Denver on Saturday, former Texas Gov. Rick Perry reiterated his support for letting states go their own way on marijuana:

Let this country compete again. I am so optimistic about the future of America if we would free up these states from this one-size-fits-all [approach]. You'll see innovation. And from time to time, a state's going to foul it up. They just are. Think about what [Supreme Court Justice Louis] Brandeis said about experimentation, and Colorado comes to mind. But I defend the right of Colorado to be wrong on that issue. It's their right.

Perry's support for marijuana federalism, a position that has attracted several of his rivals for the Republican presidential nomination, is one of the reasons he receives a B in the Marijuana Policy Project's new report card, which grades six Democrats and 16 Republicans who are officially running for the White House or expected to do so. Perry gets the second best grade among the Republicans.

The leader, unsurprisingly, is Sen. Rand Paul (R-Ky.), who beats not only the other Republicans but all of the Democrats as well. In awarding Paul an A–, MPP notes that he "has consistently supported states' rights to establish their own marijuana policies, and he has been a vocal supporter of decriminalizing or reducing criminal penalties for those arrested for marijuana possession." Paul sponsored the CARERS Act, which makes the federal ban on marijuana inapplicable to people who produce, distribute, or consume the drug for medical purposes in compliance with state law. The bill also would help state-licensed cannabusinesses, whether medical or recreational, obtain banking services.

Why the minus? Paul stops short of endorsing full-scale legalization, saying the decision (along with most other drug policy issues) should be left to the states.

New Jersey Gov. Chris Christie, who has promised to crack down on marijuana on states where it's legal if he is elected president, and former Sen. Rick Santorum (R-Pa.), who opposes legalization even for medical use and says "Colorado is violating the federal law," both receive the lowest possible grade, an F.

Among the Democrats, former Sen. Jim Webb (W.Va.) and former Rhode Island Gov. Lincoln Chafee, both of whom support marijuana federalism and are open to legalization, get the highest grade, a B+. Sen. Bernie Sanders (Vt.), who supports medical marijuana and decriminalization but remains agnostic on legalization for recreational use, comes in second with a B. Hillary Clinton, who supports medical research (who doesn't nowadays?) and marijuana federalism, gets a B–. Vice President Joe Biden, who opposes legalization, still brags about giving us a drug czar, and proudly refers to the penalty-enhancing, prison-filling "1994 Biden Crime Bill," gets a D, the lowest grade among the Democrats.

[This post has been revised to include the grade for Lincoln Chafee, whom I overlooked in the first version.]