The idea of tax breaks based on race is nothing new. Native Americans on reservations are typically exempt from the income tax. They also receive many exemptions in other taxes.
What "long-standing policy"? You don't think American Indians pay taxes?
All Indians are subject to federal income taxes. As sovereign entities, tribal governments have the power to levy taxes on reservation lands. Some tribes do and some do not. As a result, Indians and non-Indians may or may not pay sales taxes on goods and services purchased on the reservation, depending on the Tribe. However, whenever a member of an Indian tribe conducts business off the reservation, that person, like everyone else, pays both state and local taxes.
You may now continue your debate, and be able to do so with actual factual data, rather than stuff you may have heard that is not accurate...
Chad "An Indian who pays the same taxes everyone else does" Fairbanks