Why were thousands of Mexicans in the US sent back to Mexico 1930?

In the 1930s, during the Great Depression, the United States government initiated the Mexican Repatriation Program, resulting in the return of Mexican citizens and Mexican Americans to Mexico. However, the number of Mexicans sent back to Mexico was not in the thousands; estimates suggest that up to one million individuals were repatriated during this time. The primary reasons behind this large-scale repatriation were rooted in economic challenges and anti-immigrant sentiments prevalent during that period.