The last four Presidents—George W. Bush, Barack Obama, Donald Trump, and Joe Biden—saw more pro immigration policies, with the extreme exception of Donald Trump in both separate terms.
George W. Bush, similar to his father before him, promoted the general idea of the need for further immigration reform, but the September 11, 2001 attack on the World Trade Center and the Pentagon, caused him to promote extreme security measures due to the unprecedented crisis.
But Bush also supported the concept of the DREAM Act (Development, Relief, and Education For Alien Minors), which gave illegal immigrant minors the right to avoid being deported, but it suffered from great opposition from the majority of Republicans, so it only, finally, came to fruition under his successor, Barack Obama.
Under Barack Obama, the DREAM Act finally passed, and Obama also initiated by executive action the DACA program,(Deferred Action For Childhood Arrivals), which by 2017, had registered 740,000 individuals.
Obama also tried to promote DAPA (Deferred Action For Parents Of Americans And Lawful Permanent Residents) from 2014 through 2016, but it was prevented by Republican opposition, and then dropped by Donald Trump in 2017. At the same time, Obama also had record deportations of undocumented immigrants, estimated at more than three million people.
Donald Trump, in his first term, worked to build an expansion of the Border Wall with Mexico; imposed a travel ban on people from a wide variety of nations, particularly outside of Europe and the Americas; dramatically reduced refugee admissions; and promoted family separations.
Many children were left without presence of their parents, while in detention before deportation. These policies caused massive outrage and resistance.
Under Joe Biden, Trump policies on immigration were reversed; there were increased refugee admissions to the nation; and there was restored DACA (Deferred Action For Childhood Arrivals).
Upon Trump’s return to the Presidency, a totally anti-immigrant policy was pursued, including declaring a national emergency; promotion of greater border militarization with Mexico; and massive mass deportation operations, setting a goal of 3,000 immigrants per day to be arrested and sent to detention centers with horrendous conditions.
Major court cases led to lots of litigation to stop what was seen as a basic violation of civil and human rights, but with total determination by the Department of Homeland Security and the US Border Patrol to accelerate millions of immigrants being removed from the country, and with many being sent to nations they had no background in their earlier lives, and not having even the same language to be able to communicate.
Often citizens as well as undocumented immigrants, particularly those who are Latinos, or really, any person of color, have been removed, and the pace of deportation has accelerated, as the Trump Administration denies any mistreatment, and often ignores court decisions or lawsuits.
What the Trump Administration has done is the worst anti immigration policy since the internment of 125,000 Japanese Americans during World War II under Franklin D. Roosevelt; and Operation Wetback against Mexican nationals in the mid 1950s under Dwight D. Eisenhower.