Well, IIRC, there are countries like Bolivia who have many native American co-official languages. According to wikipedia, it has 37 official languages: Spanish+36 Amerindian tongues.
Some of these are widely spoken (Quichua, Aymara, etc.) but others are spoken by very few people (like many of the languages spoken in the eastern Tropical Forrest).
Of course, the reason why this languages are recognised probably has something to do with the fact that there were three widely spoken native American languages (Quichua, Aymara and Guaranni) in Bolivia and, thus, the speakers of these languges have pushed for official recognition of their languages. Recognising these and not recognising the rest would seem unfair, so, eventually, 36 languages where recognised (even if some have very few speakers, not more than those who speak some native american languages in the US).
The thing is in countries which don't have one or more widely spoken Amerindian languages, like the US, Canada or Argentina, there doesn't seem to be this pressure for making Amerindian languages official (even if there are several Amerindian languages in these countries, although spoken by few people). Even countries like Chile, with have a significant Mapuche speaking minority (3 % of the population), geographically concentrated in one region, Amerindian languages haven't been recognised.
So, even if it's theoretically possible to have an US in which many native Amerindian tongues are co-official without changing the number of speakers of native American languages, it's hard to see what Pod would push the US in such a direction.