actually it's Americans of Hispanic descent that are telling the Mexicans the facts of life.
I know. What I said was meant to be humorous, given that even the most assimilated Americans of certain Hispanic descent (it must be the country of Mexico, as a matter of fact) still refer to themselves as Mexicans, as a means of distinguishing themselves from idiotic leftist Chicanos, whom they despise and don't seek any identification with.
All my Mexican-Am friends are MEXICANS because they won't put up with anyone calling them Chicanos and they sure as heck don't like Hispanic or Latino. Therefore, they're MEXICANS!