Also, Article I, section 8 says, in part:
To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.
This is sort of the catchall that allows the US Congress to make such laws as it deems necessary to use the powers the Constitution explicity grants it. Congress has the authority to make whatever laws it sees fit. It is the job of the Supreme court to determine if these laws explicity violate the restrictions imposed by the Constitution, particularly the Bill of Rights. Thus far, the Court has not found reason to rule the laws pertaining to marijuana to be unconstitutional.

Again, to be clear, I am NOT agreeing with the laws, only with the fact that the US Congress does, in fact, have the Constitutional authority to make such laws, if it so deems fit.
Beeblebrox.420 Reviewed by Beeblebrox.420 on . Supreme Court murders California man RIP Steve McWilliams...... Friends and supporters of McWilliams, who killed himself last week in a desperate effort to end his suffering and draw attention to his cause, will gather at City Hall at noon to remember the activist who pushed San Diego into becoming the largest city in the nation to adopt a medical marijuana law. http://www.unknownnews.org/0507190717McWilliams.html Rating: 5