No they don't. At least where the majority in the local culture talks Spanish, and where the immigrant is Mexican.
There are plenty of such places in the United States. For example, 37% of the population in the Greater Los Angeles area use Spanish as a home language. This figure climbs to 40% in Miami, 72% in El Paso, and 43% in San Antonio.
This is actually true. One of my friend who doesn't know Spanish stayed in El Paso for a week and he was like hunting for English stores. Learnt lots of Spanish words, we were wondering whether he went to Paso or Spain..