The Reservations are a Sovereign State. The are protected from laws and BY laws.
Like one Chief outside of New York City said: until cigarettes are illegal, leave me alone. The FBI also ask him how many cigarettes did he sell in a day: he told them Its none of your business.
Hmmmm . . . wonder if some of the tribes gave big campaign contributions to various governors to raise tobacco taxes!!! LOL -- they must be loving it!