They should be allowed to live traditionally. The federal government dictates the way in which state governments can deal with Indian people. States can t deal with Indian people without advisement from the federal government. Federal law takes precedent in dealing with Indian people. This has implications for Indian gaming.
Every law passes by congress with regards to Indian people cutes into Indian sovereignty.
However, the extent of sovereignty and associated power is not entirely understood. Even though congress enacts hundreds of laws, it has yet to obliterate tribal sovereignty. These courts are able to create precedents for legal actions and issues. There is also the issue of dual citizenship. Although Indians are members of their own tribes and nations, they are also citizens of the United States, and subject to U.S. laws.