The movement to end marijuana prohibition has made significant progress recently, but it could all be undone when the next president takes office in 2017. Harvard economist Jeff Miron, a supporter of marijuana policy reform, highlighted the precarious nature of state marijuana laws in an op-ed for CNN on why Congress needs to act now on federal marijuana policy. "Federal law still prohibits marijuana, and existing jurisprudence (Gonzales v. Raich 2005) holds that federal law trumps state law when it comes to marijuana prohibition," Miron wrote.