Final answer:
The predominant religion in some areas of the southwestern United States may be different from the surrounding areas due to factors such as ethnicity and historical migration patterns. The Spanish conversion of Native Americans and the establishment of Catholic churches played a significant role in the prevalence of Catholicism in these regions.
Step-by-step explanation:
The predominant religion in some areas of the southwestern United States may be different from the surrounding areas due to various factors such as ethnicity, historical migration patterns, and the influence of Catholicism. For example, the Spanish converted many Native Americans in the American Southwest, which contributed to the prevalence of Catholicism in these regions. Additionally, the presence of established Catholic churches in places like California attracted Catholic immigrants over the years through a process known as chain migration.