Things are not as bad as some people think. I've long noticed that no matter how unassimilated some Mexican immigrants are, their children and grandchildren are being assimilated into our culture. (Insert your favorite Borg warning here!) I just had an example of that not 20 minutes ago.
I work in a mostly Latino neighborhood in the San Fernando Valley and get my hair cut at a local shop. The owner is originally from Mexico. The girl who cuts my hair is Latina, but she was born and raised here. The shop usually has the TV on one of the Spanish language stations. This should set the scene for you.
A customer walked in with her little boy. She asked a question in Spanish of the girl cutting my hair, who answered in Spanish. Her little boy noticed something on the wall and asked his mother about it, in English. She responded to her son in English. A few minutes later, as I was paying my bill, the little boy walked up to me and asked ¿Como estás?. (I have dark hair and an olive complexion, so I assume that he mistook me for a Latino.) How is this a good sign, you ask? The little boy, while fluent in Spanish, obviously speaks English at home. English is his primary language.
Culture is something one learns and it's determined by language, not ethnicity. The culture that child is learning is ours; not Mexico's. His mother may be trying to cling to the culture of the "Old Country", but he is turning into an American. Resistance Is Futile.