Almost universally, especially if the place doesn't identify the region of Mexico the food is from.

I've had great high-end Mexican food, in Mexico, but it's regional fare and not Americanized stuff. I've had two really good regional Mexican meals in the states. I suppose in theory you could do high-end pan-Mexican food here but I've never managed to make it to the place, and when I've been taken places that claimed to be the food was basically ritzed-up Americanized stuff.

For Cali-Mex and Tex-Mex food, if it's good, it's catering to locals and not trying to be fancy food -- it shouldn't be any pricier than say, Chevy's, and often a lot cheaper. The best are in general little taco shops; if there's no self-serve jar of radishes, it's probably not that good.