- Immigrants have long made up a significant portion of the U.S. population. In 2019, they comprised almost 14 percent.
- Congress has failed to agree on how to address immigration challenges, leaving many policy questions up to the courts and executive branch.
- President Joe Biden has reversed many of former President Donald Trump’s restrictive policies, even as he has struggled with a historic influx of migrants.
Immigration has been a touchstone of the U.S. political debate for decades, as policymakers have weighed economic, security, and humanitarian concerns. Congress has been unable to reach an agreement on comprehensive immigration reform for years, effectively moving some major policy decisions into the executive and judicial branches of government and fueling debate in the halls of state and municipal governments.
Former President Donald Trump put the issues back at the center of public debate with his unprecedented efforts to curb immigration and reshape asylum policy. President Joe Biden pledged to reverse Trump’s actions and reform the system, but the ongoing COVID-19 pandemic and a great influx of migrants have complicated his plans.
What is the immigrant population in the United States?
Immigrants comprised almost 14 percent of the U.S. population, or nearly 45 million people out of a total of about 328 million in 2019, according to the Census Bureau. Together, immigrants and their U.S.-born children make up about 26 percent of U.S. inhabitants.
The share of the population that is foreign-born has steadily risen since 1970, when there were fewer than ten million immigrants in the United States. But there are proportionally fewer immigrants today than in 1890, when foreign-born residents comprised nearly 15 percent of the population.
As of 2018, Mexico was the most common country of origin for U.S. immigrants, constituting 25 percent of the immigrant population. However, Asia was the top region of origin, with 28 percent of immigrants born there.
Undocumented immigration. The undocumented population is estimated to be about eleven million people and has leveled off [PDF] since its peak before the 2008 economic crisis, which led some to return to their home countries and discouraged others from coming to the United States. In July 2021, Customs and Border Protection (CBP) reported more than 212,000 encounters with people trying to cross the southern border, the highest monthly figure in two decades.
Roughly two-thirds of undocumented immigrants have lived in the United States for more than a decade, and many are the parents of U.S.-born children. Until 2013, almost all of those trying to cross the U.S.-Mexico border were Mexican citizens and most were individuals seeking work; since then, Central Americans have made up an increasingly large share, reaching 81 percent [PDF] in 2019. Generally, they are coming not for work but to make asylum claims, and many of them are unaccompanied children. Some of these immigrants have different legal rights from Mexican nationals in the United States: under a 2008 anti–human trafficking law, unaccompanied minors from noncontiguous countries have a right to a hearing before being deported to their home countries. The spike in Central American migration has strained the U.S. immigration system, with more than 1.2 million cases pending in immigration courts.
Though many of the policies that aim to reduce unlawful immigration focus on enforcement at the border, individuals who arrive in the United States legally and overstay their visas comprise a significant portion of the undocumented population. A Center for Migration Studies report found that, in 2010–2018, individuals who overstayed their visas far outnumbered those who arrived by crossing the border illegally.
Legal immigration. The United States granted about one million individuals legal permanent residency in fiscal year 2019, which is roughly on par with most years since the early 1990s. More than two-thirds of them were admitted on the basis of family reunification. Other categories included: employment-based preferences (14 percent), refugees (8 percent), diversity (4 percent), and asylees (3 percent). In late 2020, nearly four million applicants were on the State Department’s waiting list [PDF] for family- and employer-related immigrant visas.
Hundreds of thousands of foreign nationals work legally in the United States under various types of nonimmigrant visas. In fiscal year 2020, the United States granted close to 125,000 visas [PDF] for high-skilled workers, known as H1B visas, and more than 275,000 visas for temporary workers in agriculture and other industries. H1B visas are capped at 85,000 per year, with exceptions for certain fields.
Immigrants made up 17 percent of the U.S. civilian workforce [PDF] in 2020, according to the Bureau of Labor Statistics. Compared to those born in the United States, greater shares of immigrants worked in service fields (20.6 percent of all foreign-born people); production, transportation, and material moving (15.2 percent); and natural resources, construction, and maintenance (13.6 percent). A 2017 Pew Research Center study projected that, without immigrants, the U.S. workforce would decline by almost ten million people by 2035.
How do Americans feel about immigration?
A 2020 Gallup poll found that 77 percent of Americans surveyed considered immigration a good thing for the United States, the highest level in two decades. At the same time, however, majorities felt that illegal immigration was a significant threat and that immigration should be kept at the same level or decreased.
According to a separate poll conducted by Vox and Data for Progress the following year, 69 percent of voters surveyed—including a majority of Republicans—supported a path to citizenship for undocumented immigrants if they meet certain requirements. A greater share (72 percent) supported citizenship for immigrants brought to the United States when they were minors, who are often referred to as Dreamers.
How has Congress tried to address the issue?
The last push for a major immigration overhaul came in 2013, following a decade in which Congress debated numerous immigration reforms, some considered comprehensive, others piecemeal. (Comprehensive immigration reform refers to omnibus legislation that attempts to address the following issues: demand for high- and low-skilled labor, the legal status of the millions of undocumented immigrants living in the country, border security, and interior enforcement.) The last comprehensive legislation to make it through Congress was under President Ronald Reagan in 1986; it gave legal amnesty to some three million undocumented residents. In 2007, President George W. Bush worked with congressional Democrats to reach a compromise on a new comprehensive bill, but it ultimately failed to win enough support.
President Barack Obama pressed hard for a comprehensive bill that would pair a path to legalization for undocumented residents with stronger border security provisions. The Democrat-led Senate passed this legislation in 2013, but the bill stalled in the Republican-controlled House of Representatives. Both Trump and Biden proposed comprehensive reforms, but Congress has not considered either.
What was the Obama administration’s approach?
With legislation thwarted, Obama took several executive actions to provide temporary legal protections for undocumented immigrants. In 2012, his administration began a program known as Deferred Action for Childhood Arrivals (DACA), which offered renewable, two-year deportation deferrals and work permits to undocumented immigrants who had arrived in the United States as children and had no criminal records.
Obama characterized the move as a “stopgap measure” and urged Congress to pass the DREAM Act, legislation first introduced in 2001 that would have benefited many of the same people. Since then, more than eight hundred thousand people have participated in the program, and 1.7 million more are eligible. Obama attempted to extend similar benefits to undocumented parents of U.S. citizens and permanent residents in a program known as Deferred Action for Parents of Americans (DAPA), but the Supreme Court effectively killed the program in 2016.
In 2014, Obama also grappled with a surge of more than sixty thousand unaccompanied minors at the southern border, mostly from Central America. His administration directed $750 million in aid to the region to improve conditions there. Meanwhile, the administration faced criticism for its enforcement policies, including detaining children in poor conditions and overseeing the deportation of more people—more than three million—than either the Bill Clinton or George W. Bush administrations had.
What was the Trump administration’s approach?
Immigration was a signature issue for Trump and a perpetual source of controversy during his term. Blaming previous administrations for failing to secure the southern border, he advocated for sharply reducing both legal and illegal immigration. He took numerous steps, many through executive action, to reshape asylum, deportation, and border policy.
Border security and enforcement. Trump vowed to expand the wall along the U.S.-Mexico border, which he claimed would stop drugs and gangs from entering the country. He was unsuccessful in securing funding from Congress, leading to a federal government shutdown in 2019 and Trump to subsequently declare a national emergency, which allowed him to divert funds to the wall.
Trump also ratcheted up previous administrations’ deterrence efforts. He implemented a zero-tolerance policy, under which authorities arrested and prosecuted everyone caught crossing the southern border without authorization. This caused thousands of family separations, since by law children must be held apart from parents facing criminal prosecution. (Presidents Bush and Obama likewise faced criticism for child detention, but they did not make separations a matter of policy.)
Other enforcement measures included ordering an increase in border personnel; sending thousands of active-duty troops to the border; threatening Mexico with tariffs if it did not increase its own border enforcement; and attempting to cut federal funding to so-called sanctuary cities, or jurisdictions that refuse to enforce federal immigration directives.
DACA. Trump sought to end DACA, calling it unconstitutional. The move spurred multiple legal challenges and, in June 2020, the Supreme Court blocked Trump’s plan. A December 2020 federal court ruling forced the Trump administration to resume accepting new applicants.
Travel bans and refugee cap. Trump sought to sharply reduce the number of refugees and other immigrants granted legal entry. In 2017, he instituted a ban on immigration or travel from several Muslim-majority countries. The original order was rejected by the courts, but the Supreme Court upheld a more limited version. Trump also lowered the cap on the number of refugees the United States accepts each year to less than eighteen thousand, down from roughly eighty thousand before he took office. Additionally, he ended temporary protected status (TPS)—a program that allows migrants from certain crisis-stricken nations to live in the United States for a limited period—for several countries.
Asylum policy. Trump implemented new restrictions on asylum seekers. In 2018, the administration began “metering” asylum applications, or only accepting a limited number [PDF] each day. The next year, it launched the Migrant Protection Protocols (MPP), also known as Remain in Mexico, which required asylum seekers to stay in Mexico while their cases were pending. At the same time, it sought “safe third country” agreements with Guatemala, Mexico, Panama, and others, which would have allowed U.S. authorities to send asylum seekers who traveled through those countries back there. Only the agreement with Guatemala was implemented before that country suspended it in 2020.
Comprehensive reform effort. Like his immediate predecessors, Trump proposed a broad immigration reform. His would have created a merit-based system to replace the current one, which prioritizes family reunification. It also included expansion of the border wall and an employment verification system known as E-Verify but did not address the status of current undocumented residents.
How has the pandemic altered immigration policy?
The Trump administration further restricted immigration amid the COVID-19 pandemic by: curbing travel to the United States, effectively halting asylum procedures, turning away most migrants at the U.S.-Mexico border, and suspending the processing of many foreign worker visas and green cards.
The administration framed these changes as necessary to limit the virus’s spread and protect American jobs, but critics accused Trump of using the public health crisis to further his anti-immigration agenda. Some argued that the detention and deportation of migrants during the pandemic fueled the virus’s spread.
Despite his stated goal of reversing Trump’s border policies, Biden has maintained most pandemic-related restrictions, including limits on nonessential entry into the country. Most notably, he has kept in place a pandemic-related public health order that allows for immediate expulsion of apprehended migrants, though he has exempted unaccompanied children and some adults.
What is the Biden administration’s approach?
Biden campaigned on overturning almost all of Trump’s immigration policies. In its first months, his administration has taken dozens of actions, but his attempts to reform the system have collided with a dramatic rise in migration to the southern border.
Biden’s steps to undo Trump-era policies have included reducing immigration enforcement inside the United States, ending the travel bans, lifting the suspension of green card processing, and halting construction of the wall along the U.S.-Mexico border. His administration has also expanded TPS protections, canceled safe third country agreements, and raised the refugee cap to 62,500 after initially maintaining the limit imposed under Trump. It has additionally launched efforts to speed the reunification of migrant families, including by reinstating the Central American Minors (CAM) program, which reunites children in the Northern Triangle with parents in the United States.
However, Biden has faced roadblocks. His discontinuation of Remain in Mexico was challenged by several states and then blocked by the Supreme Court. A federal judge halted DACA, putting that program’s future in doubt. Meanwhile, a historic influx of migrants at the southern border threatens to destabilize Biden’s efforts further: after a pandemic-related drop, border apprehensions spiked to nearly two hundred thousand in July 2021, the highest level in more than twenty years. Tens of thousands of migrants, many of them children, are detained in emergency facilities. The administration has sought to address underlying causes of the crisis, promising $4 billion in new aid to Central American countries, but at the same time has issued stern warnings to would-be migrants to not make the journey.
Biden sent to Congress his own comprehensive immigration bill, which would create a path to citizenship for undocumented immigrants, expand visa and green card availability, broaden asylum eligibility, and boost border security spending. However, experts say it will be difficult for the proposal to win enough Republican support.
How are state and local authorities handling these issues?
States vary widely in how they treat unauthorized immigrants. Some states, such as California, allow undocumented immigrants to apply for drivers’ licenses, receive in-state tuition at universities, and obtain other benefits. At the other end of the spectrum, states such as Arizona have passed laws permitting police to question people they suspect of being unauthorized about their immigration status.
The federal government is generally responsible for enforcing immigration laws, but it delegates some immigration-related duties to state and local law enforcement. However, the degree to which local officials are obliged to cooperate with federal authorities is a subject of intense debate. As of 2019, almost one-quarter of U.S. counties limit their cooperation with ICE, according to the Immigrant Legal Resource Center.
President Trump decried these sanctuary jurisdictions and reinstated a controversial Obama-era program known as Secure Communities, in which the FBI shares fingerprints of suspects collected by state and local law enforcement with federal immigration authorities. Under the program, state and local agencies also hand over individuals presumed to be in the country illegally. Biden terminated the program shortly after taking office.
A range of court rulings during the Trump era increased pressure on states. In 2018, the Justice Department launched a lawsuit against California over sanctuary jurisdictions, which was ultimately dismissed by the Supreme Court. It filed similar suits against New Jersey and Washington and a federal court ruled in 2020 that the Trump administration could withhold federal funding from sanctuary jurisdictions, including New York City. Under Biden, the Justice Department has reversed this stance, leading the Supreme Court to dismiss several pending cases.
Trump’s border security policies prompted differing local reactions. After Trump called on states to deploy National Guard contingents to the southern border, several governors refused. Other governors, including Texas’s Greg Abbot, embraced Trump’s views and have vowed to continue work to expand the border wall.
The BBC lays out how Biden’s border policies differ from Trump’s.
CFR’s Edward Alden examines the effectiveness of border enforcement in this 2017 report for the Center for Migration Studies.
The Congressional Research Service provides an overview [PDF] of U.S. immigration laws.
This CFR Backgrounder explains who is responsible for securing the U.S. border.
This timeline traces changes to U.S. postwar immigration policy.
Nathalie Bussemaker and Samuel Parmer contributed to this report.