The US Supreme Court has ruled that Oklahoma can prosecute non-Native Americans for crimes committed on tribal land when the victim is Native American. This was a five-to-four decision with the "right wing" of the court (excluding Neil Gorsuch) making the majority opinion:
The exercise of state jurisdiction here would not infringe on tribal self-government. In particular, a state prosecution of a crime committed by a non-Indian against an Indian would not deprive the tribe of any of its prosecutorial authority. That is because, with exceptions not invoked here, Indian tribes lack criminal jurisdiction to prosecute crimes committed by non-Indians such as Castro-Huerta, even when non-Indians commit crimes against Indians in Indian country.
The case in question is summed up as:
The case stemmed from a state court decision to throw out the conviction against Victor Castro-Huerta, who is not Native American. Castro-Huerta was charged by Oklahoma prosecutors with malnourishment of his disabled five-year-old stepdaughter, a member of the Eastern Band of Cherokee Indians.
My understanding is that the right wing is usually considered "orginalist", defined by wikipedia as:
originalism is a concept regarding the interpretation of the Constitution that asserts that all statements in the constitution must be interpreted based on the original understanding "at the time it was adopted"
It would seem to me that at the time when these treaties were signed childhood malnutrition would have been much more of an issue than it is today, certainly for the Native tribes, and avoiding people being prosecuted for these life and death decisions would have been an important factor to the Muscogee and other Native tribes that made this agreement. Non-native men marrying native women would also have been a thing that happened at the time and would have been considered by those making this agreement. Therefore an orginalist would be inclined to support the tribal sovereignty in this case. On the other hand, someone who supported the Living Constitution, or judicial pragmatism may be more likely to consider that childhood malnutrition is avoidable today, and the state would be better if it is able to prosecute people in this situation.
Is this a valid reading of the issues? Is this an example of the right wing of the US Supreme Court taking a less orginalist position that the left wing?