Sounds great. Remember that the point is not to persuade the cultist. It is impossible to persuade a cultist. It is to strip him of the protection of mainstream opinion. By moving from "Indians have more rights because they were indigenous" (which will have some mainstream support) and forcing him into a lose-lose position, you can win any argument with him, even if he does not acknowledge it.
Sounds great. Remember that the point is not to persuade the cultist. It is impossible to persuade a cultist. It is to strip him of the protection of mainstream opinion. By moving from "Indians have more rights because they were indigenous" (which will have some mainstream support) and forcing him into a lose-lose position, you can win any argument with him, even if he does not acknowledge it.