Name one key legal authority that empowers the Border Patrol.

The Immigration and Nationality Act serves as a crucial legal foundation for the Border Patrol, empowering its agents to enforce immigration laws and maintain the integrity of the nation's borders. This act outlines the framework for immigration policy, including the authority to detain and remove individuals who are found to be unlawfully present in the country. It specifically grants border enforcement personnel the capabilities necessary to perform their duties, such as inspecting individuals and goods entering the United States.

In contrast, the other legal authorities listed have different focuses. The Customs Act primarily addresses customs regulations and the collection of tariffs, while the Homeland Security Act focuses more broadly on safeguarding the nation against various threats, without specifically delineating authority for immigration enforcement. The National Defense Authorization Act involves military funding and defense-related matters, which do not specifically empower Border Patrol operations in terms of immigration control. Thus, the Immigration and Nationality Act is the key legislation that fundamentally supports the operational authority of the Border Patrol.