Loretta Sanchez (D-Calif.)
Jim McDermott (D-Wash.)
Dana Rohrabacher (R-Calif.)
Ron Paul (R-Texas) (yeah repeat)
Senator Jim Webb (D- Va)
All of whom have endorsed legalization.
Also although not specifically stated we cannot exclude Obama himself from the "in favor of letting states choose" side based on this statement from the oval office I previously quoted:
The president believes that federal resources should not be used to circumvent state laws
Actual federal legalization is hindered because we would have to renig on treaties we pushed on the rest of the world in order to pull it off.
The loophole is this:
Single Convention on Narcotic Drugs - Wikisource1. (a) Subject to its constitutional limitations, each Party shall adopt such measures as will ensure that cultivation, production, manufacture, [ect.]...
...shall be punishable offences when committed intentionally
Although a question of interpretation (and a harbinger of future SCOTUS challenges), States rights can be considered a constitutional limitation.