As the debate rages on about whether illegal immigrants do our country more harm or good, one question rarely gets asked; with so many Mexicans living in the U.S., legally or not, why is it so hard to find good, authentic Mexican food?

Author Dagoberto Gilb, who often contemplates Chicano culture, laments the proliferation of lousy, pseudo south-of-the-border-inspired fast food that is no more representative of true Mexican cuisine than the Olive Garden is authentically Italian.

Gilb observes that the original Taco Bell stand, like the first McDonald's, opened in San Bernadino, California. Both food chains built their fast food empires on greasy, fatty meats and cheese served with wilted, ultra-white iceberg lettuce, and anemic, pink tomato slices. Is one more authentically American than the other?

While living near Santa Barbara, Gilb overcame his wariness of "hippie fusion Mexican food," and developed a taste for alfalfa sprout-filled burritos and spinach and mushroom tacos. But he also loves real Mexican enchiladas, dredged in chile, filled with a bit of meat and topped with queso fresco. He raves about ceviches, heuvos rancheros and sweet onion-filled tacos, too.

"Mexican food is not, by nature, unhealthy," he points out, "or not more so than French or even Chinese food is. Yet Taco Bell romanticizes the most fattening character of both popular American and Mexican food."

Gilb revisited Taco Bell to satisfy his own curiosity about what, in Taco Bell terms, constitutes a chalupa. According to the Taco Bell cashier who took his order, a chalupa is just like a taco, only bigger. Gilb ordered one of each:

"I ate them both, and let me tell you unambiguously...how genuinely awful the meat was," he writes. "Both the chalupa and the taco were so sincerely awful, a food thinking so outside the bun, that I can't even praise the few chunks of tasteless, if still possibly a little healthy, tomato."

"Taco Bell's seasoned ground meat isn't picadillo because it isn't Mexican. The taco and its filling are American now." Apparently, assimilation is not always a good thing.

Obviously, no one goes to Taco Bell expecting to find real Mexican food, but their bland, bastardized interpretation of Mexican cuisine has achieved such popularity on this side of the border that even the most authentic-looking taco stands are often no better.

We learned this the hard way on a visit to San Diego last December, at a promising little taco stand called Roberto's. It looked exactly like the kind of place that might have good taquitos, or real frijoles. But the choices on the menu board were limited to variations of quasi-Mexican combo platters.

Disappointed, but hungry, we ordered anyway, and hoped for the best. Ironically, it turned out to be the worst Mexican food we have ever tasted, hands down. It was so bad that Matt became ill; he claims that he has not yet fully recovered, four months later.

Next time, we'll look for the nearest Chipotle's. Its accent may be no more authentic than Taco Bell's, but at least Chipotle's relies on high quality ingredients, freshly prepared. Their motto is "Food With Integrity," and that's a concept that works in any language.