The issue is that they aren't the ones that made the law, they're just the ones tasked with enforcing it, and they can initiate proceedings to change the schedule of a substance. And until the FDA gets their crap together and conducts some serious research(Which should be easier now, since the DEA has eased up on research restrictions and growing for research purposes), it probably won't change. Until the FDA comes out and says that marijuana has proven medical benefits, the DEA isn't obligated to change anything. Granted, they probably like it that way, but still, there's nothing on the federal level to give them a reason to change the schedule of marijuana. So basically, they've acknowledged that marijuana may have some redeeming medicinal qualities, so they've eased up on research regulations to make it easier to prove that it has medicinal qualities.
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