Indians native to Mexico though --- one reason the Spanish government invited "anglos" into the northern territories like Texas was because the Indians gave them so much trouble, no Mexicans would move into them.
"Indians" is a misleading term anyhow -- it's not like Indians were ever one big happy family or one united people --- they were many separate groups which often raided each other and went to war. The Indians of Mexico are different tribes than the ones who were here -- except for a few --- so being Indians doesn't entitle them to the land which belonged to other Indians groups.
Before the "Anglos" were invited to settle in Texas, the Spanish/Mexican population was actually declining because they were unable to defeat the Indians and so were leaving.
"Indians" is a misleading term anyhow -- it's not like Indians were ever one big happy family or one united people --- they were many separate groups which often raided each other and went to war. The Indians of Mexico are different tribes than the ones who were here -- except for a few --- so being Indians doesn't entitle them to the land which belonged to other Indians groups.
Contrary to popular belief, New World "Indians" are not a monolithic race. Different tribes are descended from different groups of east Asians. There is an ethnic difference between a Mayan Indian from Mexico and an Athabasca Indian from Canada.