So ignore the statement as a red herring and continue making the points you listed. A valid response. They will still harp about the poor native Americans, but I suppose you aren't going to convince them no matter what you say. These arguments are to benefit any third party reading.
People throughout history have overtaken lands. Romans took over England before the Saxons before the Danes.
The question of native is irrelevant. It’s a question of what culture we want to succeed us - do we want our culture to persist or do we want to be overtaken like the Babylonians or the Egyptians or the native Americans?
It’s a question of what culture we want to succeed
Yes, this.