“Hispanization” has been the norm in Mexico since the late 17th century when King Charles II of Spain forbade Mexican settlers from speaking indigenous languages. While colonial edicts from across the ocean helped Spanish become the accustomed public language in Mexico, on a local level most people kept talking the way they talked, especially in Native American communities, where many indigenous languages dot the linguistic landscape. Only in 1990s did the Mexican government begin to protect the nation’s rich linguistic resources, eventually amending the constitution to require official support for linguistic diversity. Today Mexico recognizes the use of over 60 indigenous languages.
(By the way, you think Spanish is just “Spanish?” Think again.)