When discussing the impact of immigrants crossing the border illegally on the USA, it is important to consider both the negative and positive aspects. While there are challenges associated with illegal immigration, there are also potential benefits.

Negative Impacts

Economic Strain: Critics argue that undocumented immigrants place a burden on the economy by competing for jobs and accessing public services without contributing through taxes. This strain can be particularly felt in sectors such as agriculture, construction, and hospitality.
Security Concerns: The lack of proper documentation raises concerns about national security and the ability to effectively screen individuals entering the country. Critics argue that this can potentially allow criminals or individuals with malicious intent to enter undetected.
Strain on Resources: The increased demand for resources, such as healthcare and education, can strain local communities, especially those near the border. This strain may lead to overcrowded schools and hospitals, impacting the quality of services provided to both immigrants and citizens.

Positive Impacts

Economic Contributions: Studies have shown that undocumented immigrants contribute to the economy through labor, entrepreneurship, and consumption. They often take low-wage jobs that are difficult to fill, contributing to economic growth and productivity.
Cultural Diversity: Immigrants bring diverse perspectives, traditions, and skills that enrich American society. This cultural diversity fosters innovation, creativity, and a vibrant social fabric.
Entrepreneurship and Innovation: Many successful American companies were founded by immigrants or children of immigrants. Immigrants often possess entrepreneurial drive and innovative ideas, leading to job creation and economic development.

It is important to note that the impacts of illegal immigration can vary depending on the context and the specific circumstances of individual immigrants. While there are valid concerns regarding the rule of law and national security, it is also crucial to consider the potential benefits that immigrants bring to the country.

References:
Orrenius, Pia M., and Madeline Zavodny. "Do unauthorized immigrants overuse public benefits?." Journal of Policy Analysis and Management 34.2 (2015): 456-81.
Peri, Giovanni. "The effect of immigrants on US employment and productivity." Handbook of the Economics of International Migration 1 (2014): 211-56.
Chiswick, Barry R., and Paul W. Miller. "Immigrant earnings: Language skills, linguistic concentrations and the business cycle." Journal of Population Economics 11.3 (1998): 369-91.