However they were ultimately struck down by the political expansion of European settlers. If there were some actual Indian states, independent from the US, then the natives would have a chance to endure. Maybe a US-screw scenario, in which the British Indian Reserve develops into a confederacy of native states (somewhat similar to princely states in the British Raj)?Their biggest problem is their low population after the introduced diseases. The Cherokee for example were well organized land owners with towns and newspapers. However, by the time that they modernized they were dramatically outnumbered by the Americans.
Native American populations either need to rebound faster from the plagues or European settlement of N. America needs to be slower.
1) Making the natives more resistant to the European introduced diseases is practically the only way they have any chance to push-back or at least hold onto what they have before contact.
2) Let the Aztecs not be overbearing oppressors that they were OTL. Then their conquered neighbors might be less likely to join up with Cortez to overthrow them.
That's going to require a POD well before Columbus (the date specified in the OP). Indeed, it would probably require one closer to 12000 years ago.Just reverse the diseases - have the Europeans introduce syphilis to the Americas while they take smallpox back to Europe.