Federal law bans all marijuana but, in 16 states and Washington, DC, it's legal as medicine. As a candidate, Barack Obama said he would not "circumvent state law," and his administration discontinued the high-profile raids of the Bush years. But now those raids have resumed, and local officials implementing state laws are being threatened with federal prosecution. The crackdown has growers, distributors and patients accusing President Obama of breaking a campaign promise. But some law enforcement officers and two Governors think it’s time to change the drug’s federal classification.