While the Immigration and Nationality Act of 1952 (INA) is the primary statute governing United States immigration law, and serves as the foundation, immigration laws are codified across multiple titles, chapters, and sections of the United States Code (U.S.C.). The primary constitutional authority allowing Congress to pass these laws stems from Article I, Section 8, Clause 4 of the U.S. Constitution, which grants the federal government the power to establish a uniform rule of naturalization.
Most of the federal immigration law is codified under Title 8 of the U.S. Code (Aliens and Nationality), where the original sections of the INA are converted into standardized federal law. Chapter 12 (Immigration and Nationality is the core of the INA. It dictates everything from visa allocations to deportation rules. It established grounds for why a non-citizen may be denied entry and grounds for deportation/removal. It set the statutory framework for seeking asylum and changing from a temporary nonimmigrant visa to Lawful Permanent Residency (a Green Card).
Because immigration intersects with national security, employment, and criminal law, major rules also sit within other titles of the United States Code:
Lastly, the Code of Federal Regulations (CFR) gives Federal agencies permission to write specific rules to enforce these statutes. For instance, Department of Homeland Security regulations are tracked under Title 8 of the CFR, and Department of State regulations fall under Title 22 of the CFR. Executive Orders & Presidential Directives gives the executive branch ability to use these tools to prioritize border enforcement strategies, manage refugee admissions limits, or pause certain deportations within the bounds of the existing statutes.
Following his return to office, Trump issued sweeping executive actions invoking Section 212(f) of the Immigration and Nationality Act (codified as 8 U.S.C. § 1182(f)) to suspend the entry of migrants at the southern border—including asylum seekers—under the legal theory that an unconstitutional "invasion" was occurring. The actions also barred entry to anyone who could not provide extensive medical or criminal background history, which Joe Biden could have done at any time, but instead he temporarily suspended the entry of noncitizens crossing between ports of entry when daily border encounters exceeded a rolling average of 2,500.
