So the issue is more complicated than you state.
* addendum since this is likely flame bait. The Cherokee, having been betrayed by Andrew Jackson and by the United States in general, had plenty of reason to support the confederacy. Have a look at Wikipedia for a historical overview:
https://en.wikipedia.org/wiki/Cherokee_in_the_American_Civil...
The city of Yakima was found [1] to have violated the Voting Rights Act a few years back because they have a significant Latino minority and yet somehow no Latinos would ever be elected to city council. This is because every voter votes on every city council seat, and because the town's majority of white voters apparently has a preference for white candidates.
I don't remember what the solution was, I think they either split the town into districts, each with its own city council member, or used some kind of proportional representation system.
[1] https://www.aclu.org/press-releases/federal-court-rules-yaki...
It doesn't work like that when you make a deal with the government. Just ask a native American if you don't believe me. :)