They were to Mexico what the Cherokee and so on are to the USA.
I say "were" since they're effectively gone. Their descendants still exist though across Mexico, but that's a distant relation and nothing more. In 2000, there was an estimated 1.5 million that spoke the Aztec language of Nahuatl. Quite a big number, but I'm sure it's considerably less now. Anyway, I wouldn't buy any living person's moaning as speaking for the Aztecs though.