There are places in Mexico where you don't have to worry about changing your money. In Tijuana and Cancun, even as far inland as San Miguel de Allende (at times), you're greenbacks might be welcomed.
In Dallas, Texas, it appears the opposite is true: at Pizza Paton, "acemptamos pesos" is now the part of daily business. The chain, which has 59 pizza shops started accepting pesos as legal tender for their pizza on Monday. The owner, Antonio Swad, expected to take some heat from the promotion, but he was surprised when he started receiving death threats.
It is not uncommon for businesses along the U.S.-Mexico border to accept both currencies, and a similarly, Canadian dollars are often accepted along the U.S.-Canada border.
The significance of this reaction is that a simple business promotion has become an immigration flashpoint, exposing American insecurity about the Latino, and Mexican influence on American culture.