Even if Mexico were annexed by the USA, would the Americans be able to not only hold on to it, but assimilate the Mexicans and create 126 million new Americans?

https://www.quora.com/Even-if-Mexico-were-annexed-by-the-USA-would-the-Americans-be-able-to-not-only-hold-on-to-it-but-assimilate-the-Mexicans-and-create-126-million-new-Americans