check out the opinions at the end of this link and it will give you an idea of what is at stake.
I work with this type of program and can tell you the white county and local law enforcement think that prosecuting white men who rape indian women is a joke and you can't find one prosecution that went to trial and was convicted in the last 100 years.
It is such a joke on the reservation that they try to protect them selves but if an indian woman is found alone she is fair game.
One night a woman called the shelter - she had been raped and one of the counselors met her at the hospital where the ambulance dropped her off. She had also been beaten. The guy was known and because he was white the FBI didn't come to the hospital until after she was discharged the next day, the BIA said it wasn't in their jurisdiction because it was federal and the local cops wouldn't even accept the report, etc. Tribal lawyers said there wasn't anything they could do.
Tell republicans to pass this bill now and quit protecting rapists.