[quote]Where do you get your statistics? I know that this is only anecdotal, but every Mexican-American I know speaks English. Even amongst their Mexican-American friends and families. And I know a lot of Mexican-Americans.[/quote]

You can look here

http://dq.cde.ca.gov/dataquest/LEPbyLang2.asp?cChoice=LepbyLang2&cYear=2007-08&TheCounty=37%2CSAN%5EDIEGO&cLevel=County&cTopic=LC&myTimeFrame=S&submit1=Submit

and compare numbers of English learners and numbers of “Fluent English proficient” by grade and native tongue. An English learner is redesignated “Fluent English proficient” if he passes the test. Hispanics are doing worse than any other major group except Somalians. Grade 6 is a good reference. Ratios for grades 10-12 would be skewed because students with bad English would drop out at a disproportionally high rate. Hispanics in general have a 25% high school dropout rate, so it is significant.