How could there be a much larger proportion of the North American population that is Native? Is this ASB? The Native Americans of North America, from the Maya to the Inuit used to be much larger. Is there any way the U.S. or Canada could have ended up more like Mexico, with a considerable Native population and a strong indigenous tint to the cultures there like is somewhat in the Mexican-to-Fuegian region? Would a U.S. with a stronger Native tint to its identity have been even more consumed with Manifest Destiny, desiring and forcibly attempting to conquer all of Canada and Mexico in order to create a union of the American peoples?
The problem is that the british colonies differ fundamentally from their spanish counterparts. The spaniards basically just replaced the upper class of their american colonies with themselves, and left the rest of the natives alone and never made serious attempts to transplant their whole civilisation to the Americas.
The british on the other hand did just that, they brought their complete society to the Americas. And this left no space for the native population, which was therefore expelled. It was this process which lead to mutal killing and ultimatly the extinction of much of the Indians.
So if you want to have a stronger native presence you will have to change the colonisation pattern of north america. I see two ways to achieve this:
first you could let the british win the ARW. They were against further expansion of the colonies (which was one of the reasons for the revolution) so their victory will delay the colonisation significantly.
The other possibility would be that the french are never expelled from north america. This will lead to a division of the tribes in pro french and pro english. In the end you would get a french nation which incorporates its former allies and an english nation which does the same.