The Texas Health & Human Services published a report on this topic. One of the reasons is a high birth rate among Hispanics. About 89% of the residents in border cities identify as Hispanic/Latino. A high percentage have part-time, unskilled jobs.

Here is the link:

https://www.dshs.texas.gov/hivstd/reports/border/sec3

Por que son mas vulnerables, en caer en pobreza y desempleo

Border cities between the US and Mexico often have higher poverty rates due to factors such as economic disparity, limited job opportunities, lower wages, and social challenges related to immigration and cross-border trade. Economic conditions and infrastructural issues in these areas can exacerbate poverty levels.

Border cities between the US and Mexico often have higher poverty rates due to factors like economic disparities, limited job opportunities, lower wages, and high costs of living. Additionally, these areas may face unique challenges related to trade, immigration, and infrastructure that exacerbate poverty.