Food is deeply ingrained in cultural identity, and is one way to learn about a community’s heritage, familial customs and values. In the U.S., Mexican food is one of the most popular cuisines, with 1 in 10 restaurants serving Mexican, according to recent findings from the Pew Research Center. This trend reflects an expanding Mexican American population, with 37.2 million people or 11.2% of the U.S. population tracing their ancestry back to Mexico.
No. America is absolutely massive and not homogenous.
There may be some areas without authentic Mexican food, but if you go anywhere within ~50 miles of a major city, you can usually find an authentic Mexican restaurant.
That said, they’re both great. Tex-Mex can also be great. They’re completely different types of food.