28 U.S. Code § 3702 - Unlawful sports gambling
It shall be unlawful for—
(1) a governmental entity to sponsor, operate, advertise, promote, license, or authorize by law or compact, or
(2) a person to sponsor, operate, advertise, or promote, pursuant to the law or compact of a governmental entity,
a lottery, sweepstakes, or other betting, gambling, or wagering scheme based, directly or indirectly (through the use of geographical references or otherwise), on one or more competitive games in which amateur or professional athletes participate, or are intended to participate, or on one or more performances of such athletes in such games.