Republican former president Donald Trump is promising to ramp up deportations from the United States to historic levels if reelected to another four-year term in the White House as part of his campaign to defeat President Joe Biden, a Democrat, who has struggled with record numbers of migrants caught crossing the US-Mexico border illegally.

In June, Biden implemented a sweeping, new asylum ban aimed at quickly deporting more recent border crossers to their home countries or Mexico.

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Even with the tougher border policy, Biden has continued to work to protect longer-term immigrants in the US illegally, including through a new effort also announced in June that would ease the path to citizenship for hundreds of thousands of people married to US citizens. He has shifted enforcement priorities inside the country to focus on removing migrants who the US has deemed as public safety threats.

Faced with much higher numbers of migrants arriving at the border, Biden greatly increased deportations – including those of families – in the federal fiscal year 2023 and the first five months of the 2024 fiscal year, outpacing Trump

Trump’s pledge echoes his 2015 campaign promise to deport some 11 million immigrants in the US illegally. After winning office in 2016, he said his administration aimed to deport 2 million to 3 million people with criminal records.

But during Trump’s term in office from January 2017 to January 2021, deportations by US immigration and border authorities fell lower than most years of his Democratic predecessor Barack Obama, who some advocates for immigrants dubbed the “deporter-in-chief”.

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Biden had even fewer deportations than Trump during his first two years in office. But, faced with much higher numbers of migrants arriving at the border, he greatly increased deportations – including those of families – in the federal fiscal year 2023 and the first five months of the 2024 fiscal year, outpacing Trump.

During the first presidential debate on June 27, Trump was asked to explain how he would deport millions of people but declined to give details, saying, “We have to get a lot of these people out and we have to get them out fast.” Biden highlighted a recent drop in migrants illegally crossing the US-Mexico border under his new asylum ban but did not directly address the efforts to step up deportations.

US Immigration and Customs Enforcement agents can deport both those arrested at the border and immigrants who have been living in the country illegally for years. In addition to ICE deportations, there are other ways the government removes migrants from the country. Many recent crossers are quickly deported by officials from US Customs and Border Protection, which is separate from ICE, or sign documents agreeing to voluntarily return to their home countries. Both agencies are part of the US Department of Homeland Security.

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Single adults can be encountered by immigration authorities and placed into deportation proceedings in a number of ways. (Unaccompanied children are subject to different processes.)

Trump’s mass deportation pledge

Trump in an April interview with Time magazine said he would lean more on local police to turn migrants over to ICE. During his term in office, however, some police forces limited cooperation with federal immigration authorities. Trump in the interview said he would turn to the National Guard if needed. Tom Homan, a former top ICE official who could return in a second Trump administration, told Reuters the National Guard, if used, would play a support role but that only law enforcement officers would make immigration arrests.

According to a May Reuters/Ipsos poll, a majority - or 56 percent - said most or all immigrants in the US illegally should be deported, though the same poll suggested some Americans may be wary of some harsher deportation plans

According to a May Reuters/Ipsos poll, a majority - or 56 percent - said most or all immigrants in the US illegally should be deported, though the same poll suggested some Americans may be wary of some harsher deportation plans. About half of those surveyed opposed putting immigrants in the country illegally into detention camps while awaiting removal.

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Trump in the Time interview downplayed reports that he would build detention camps if reelected, saying he “would not rule out anything” but there “wouldn't be that much of a need for them”, suggesting people would be removed quickly. Trump campaign spokesperson Karoline Leavitt said Americans support mass deportations, and reiterated the former president’s pledge.

“On Day One back in the White House, President Trump will begin the largest criminal deportation operation of illegal immigrants and restore the rule of law,” Leavitt said in a statement.

White House spokesperson Angelo Fernandez Hernandez touted Biden’s recent actions to deter illegal immigration as well as efforts to open up more legal pathways for would-be migrants outside the US, saying Biden's asylum ban would "ensure that those who cross the border unlawfully are quickly removed".

Biden and the border

During Biden’s term, the number of people apprehended at the US-Mexico border has reached record highs.

Biden’s administration for several years used a Trump-era border expulsion policy, known as Title 42, to quickly send many migrants back to Mexico. The public health measure, put in place in March 2020 at the beginning of the COVID-19 pandemic, aimed to minimize the time migrants spent in custody and allowed border agents to rapidly expel them to Mexico without a chance to seek asylum.

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Border agents expelled migrants 2.8 million times under Title 42. The vast majority of those expulsions happened under Biden, who took office in January 2021, until he lifted the measure in May 2023 when the COVID emergency ended.

Citing these and other measures, such as increased cooperation with Western Hemisphere countries to curb migration, the US Department of Homeland Security said it has ramped up the number of removals of recent border crossers after the end of Title 42 and sped up the asylum screening process

Migrants expelled under Title 42 were not subject to the same consequences of a more formal deportation process, which can lead to criminal charges or long bars on reentering the country. The Biden administration argued that the quick expulsions led to more people attempting to cross the border multiple times and when it lifted the measure, US officials implemented new policies aimed at more effective enforcement.

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Biden has repeatedly said the only way to fix the border is through legislation. A bipartisan bill proposed in the US Senate, and backed by the White House, would have toughened border rules and increased funding. But Republicans scuttled the effort after Trump came out against it, saying it would not sufficiently stem crossings. Biden called it an “extremely cynical political move” by the former president.

Unable to pass legislation in Congress, Biden has taken several executive actions to limit access to asylum, while increasing legal ways to enter the country - including by seeking an appointment at legal ports of entry on a government-run app.

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Citing these and other measures, such as increased cooperation with Western Hemisphere countries to curb migration, the US Department of Homeland Security said it has ramped up the number of removals of recent border crossers after the end of Title 42 and sped up the asylum screening process.

Trump has said he would reinstate Title 42 if elected.