I was just reading this article by Stanford University's Dr. Tomas Jimenez published last year in one of the leading journals of sociology.
So yes, Mexican immigration is definitely a force in the U.S.-Mexican/Mexican American community. If you look at these maps, however (see below), it's not so much "immigration," but rather that a sociopolitical boundary called the "U.S.-Mexico border"—itself an artifact of violence and aggression—divides us. This fact of history that is linked to imperialist aggression and so-called "manifest destiny," perennially establishes an inescapable circumstance of "replenishment" that no fence, wall, or border will ever eliminate. Nor should it. We are well served in this country by this in so many ways.
As for our Central American "emigrés," they are our ancestral cousins and should be welcomed as they have never left their ancestral homeland, not even when they cross into the U.S. The same applies to all Indigenous peoples of this continent.
Mexican Immigrant Replenishment and the Continuing Significance of Ethnicity and Race1 | American Journal of Sociology: Vol 113, No 6
Tomás R. Jiménez, "Mexican Immigrant Replenishment and the Continuing Significance of Ethnicity and Race," American Journal of Sociology 113, no. 6 (May 2008): 1527-1567.
"The literature on assimilation and ethnic identity formation largely assumes that the durability of ethnic boundaries is a function of the assimilation measures that sociologists commonly employ. But this literature fails to account adequately for the role of immigration patterns in explaining the durability and nature of ethnic boundaries. Using 123 in‐depth interviews with later‐generation Mexican Americans, this article shows that Mexican immigrant replenishment shapes ethnic boundaries and ethnic identity formation. The sizable immigrant population sharpens intergroup boundaries through the indirect effects of nativism and by contributing to the continuing significance of race in the lives of later‐generation Mexican Americans. The presence of a large immigrant population also creates intragroup boundaries that run through the Mexican‐origin population and that are animated by expectations about ethnic authenticity. The article illustrates the importance of immigrant replenishment to processes of assimilation and ethnic identity formation."