Immigration Logic of Southern California Latino Students

I am not impressed by the logic or political savvy of Southern California Latino students who have been demonstrating for several days in opposition to immigration restriction bills currently before Congress.

Why do they think that non-Mexican Americans will be persuaded of the rightness of their cause when they wave Mexican flags?

If they want immigration from Mexico to be unrestricted so that their relatives and others in Mexico can come to the US to obtain better lives, why do they also carry banners calling for return of the Southwestern US to Mexico? Imposition of the social and economic structure of Mexico on the US would simply reproduce the kind of misery that 40% of Mexicans say they want to escape by moving to the US. Mexico is a de facto caste society, with racially based exclusion of native Americans,  ownership of the majority of property and income and control of the government in the hands of a ethnic Spanish-legacy minority, and a nearly impoverished Mestizo middle class living off state bureaucracies. Mexico is a morally, ideologically, and socially failed society. If American students of Mexican descent are so eager to live in such a society, they should go sneak across the border into Mexico and live there.