An Overview of U.S. Immigration Laws Regulating the Admission and Exclusion of Aliens at the Border

Source: Hillel R. Smith, Congressional Research Service, CRS Legal Sidebar, LSB10150, June 15, 2018

Reports of a “migrant caravan” traveling from Central America to the United States have sparked considerable attention on the treatment of non-U.S. nationals (aliens) without legal immigration status who are arrested at or near the U.S.-Mexico border. The “caravan” comprises aliens primarily from Honduras, many of whom purportedly came to the United States to escape crime and political instability in their native countries. In recent months, there has been a marked increase in the number of apprehensions of aliens at the border seeking to unlawfully enter the country, with roughly three times as many border apprehensions in May 2018 compared to the same time last year.

In response to this influx of unauthorized border crossings, President Trump and other administration officials have called for stricter immigration laws and enhanced border security. In addition, the Department of Justice (DOJ) has announced a “zero tolerance” policy to criminally prosecute aliens who unlawfully enter the United States at the southern border; a policy which has reportedly led to the separation of children from parents awaiting prosecution for unlawful entry. The Administration and its supporters argue that these policies serve as a “tough deterrent” that is necessary to curb illegal border crossings. Opponents of these policies claim that U.S. immigration laws offer inadequate protections for those seeking a “safe haven” in the United States, and some have also legally challenged the separation of families on constitutional grounds.

The situation at the border and U.S. immigration authorities’ response to it has prompted significant attention and, in some cases, confusion regarding the governing laws and policies. This Legal Sidebar briefly examines the laws governing the admission and exclusion of aliens at the border, including the procedures for aliens seeking asylum and the circumstances in which arriving aliens may be detained. The Sidebar also addresses special rules concerning the treatment of unaccompanied alien children (UACs), as well as legislative proposals that would alter the scope of protections for arriving aliens at the border. A concluding Table provides an overview of the existing laws governing the detention and removal process for aliens.