I Hate Racism and Discrimination

Earlier, I made a post about how I prefer to be referred to as Native American rather than American Indian since I feel the latter term is a bit outdated these days and someone commented saying that I'm not really Native American because my people migrated to this land from Asia, that to do so is discriminatory because we all share the same origins. He wasn't wrong about all humans sharing the same origins but me identifying as Native American is discriminatory? Really? I told him I don't agree and that just because we all share the same roots doesn't mean we can't identify with our own cultural heritage. Then he went off calling me a hypocrite and saying I'm an example of why "people" (more like he himself) don't think highly of Native Americans' ability to learn. Nice! And I'm the one being discriminatory? He's not the first to tell me I can't identify as Native American because of our origins and he probably won't be the last. He came off as just another racist and that's not a word I use lightly. I wonder if people like him would make the same case for Europeans or Asians or whatever? Probably not.