So you think in the big picture "taco bender" isn't racist, huh? Well if we're going to play games, fine, it's not racist if there's no such race, but it's an insult of a particularly low sort revealing a vulgar prejudice among it's speakers. That better?
The point bears elaboration. The principle tool that ethnic nationalists - like the irredentist Mexicans - have used to intimidate the United States is the manipulation of the concept of race. Consider this statement:
The Nixon Administration invented racial quotas in 1969 for the not unreasonable purpose of punishing Philadelphia's all-white, all-Democrat crafts unions for blatantly discriminating against blacks. But the Nixonites soon established two far-reaching precedents. They allowed affirmative action to be extended to immigrants and in 1973 created the non-racial category of "Hispanics." These seemingly minor bureaucratic maneuvers transformed affirmative action from a system limited to a few tens of millions of American beneficiaries to one with billions of potential beneficiaries worldwide.Because the Nixon administration needed a short term issue to neutralize criticisms of "racism" itself, it fabricated a new race - Hispanics. It was not supposed to be a new race, but that's what people take it as, because the other affirmative action compartment of major interest is of course racial in applying to African-Americans.
In so doing, they conferred a victim group status on 600 million people who live in Central and South America, and the Iberian Peninsula ("Spain"). A group of people who have never been in the United States, and should they arrive here, will have done so out of their own choice, not under any compulsory act by us, and with no history of "discrimination" by us to bear.
This has far reaching consequences: Congressional districts are redistricted to ensure the election of "Hispanic" candidates (know of any court orders mandating, say, a Czech district in Northern Ohio? No? Why not? It makes as much sense, according to these rules); Hiring in almost all jobs is done to accomodate de facto quotas; and any objection to illegal immigration from "Hispanic" countries is always decried as "racist". In fact, the outrage over this shooting incident on the border will almost certainly be labeled "racist" at some point by the Mexican government, which has quickly learned how to silence any opposition in the U.S. by screaming "racist" at the earliest opportunity.
This is why your use of the nullification word "racism" in an inappropriate application merits criticism, and it is not a trivial thing. In fact, as the "Hispanic" population grows, and asserts more aggressively the self-serving notion that foreign born Hispanics or even first generation Hispanics should somehow be privileged in law over 10th generation whites, it may become the defining controversy of American politics.
So carelessly using the race criticism with regards to Hispanics is not a little thing, or even a technicality. It may become the fissure that cracks American society.