According to Part B of the Controlled Substances Act the Attorney General has the power to reclassify controlled substances, full text here
http://www.fda.gov/regulatoryinformation/legislation/ucm148726.htm
In order to be classified as schedule I, the substance must have no currently accepted medical use in the United States.
The FDA has approved Tetrahydrocannabinols (THC) for medical use in 2004.
http://www.fda.gov/ohrms/dockets/dockets/05n0479/05N-0479-emc0004-04.pdf
THC continues to be listed as a schedule I controlled substance. Please have the Attorney General utilize the powers granted via the Controlled Substances Act to re-evaluate the classification of THC.