Sen. Tom Coburn (R-Okla.) introduced legislation in the U.S. Senate today that sought to undermine the 13 state medical marijuana laws. Coburn’s legislation was defeated in committee (13-10) on a party-line vote. Offered as an amendment to the Family Smoking and Tobacco Control Act, Coburn’s legislation would have placed state medical marijuana laws under the regulatory control of the FDA – not necessarily a bad thing on its own. But Coburn's intentions become apparent when you realize that FDA approval…