Homeland Security Secretary John F. Kelly signed new guidelines on Saturday giving federal authorities the power to more aggressively crack down on illegal immigration, marking what experts call a major shift in US immigration policies.

Under the new guidelines, outlined in a pair of memos, the agency plans to hire thousands of additional enforcement agents, expand the pool of immigrants who are prioritized for removal, enlist local law enforcement to help make arrests, and speed up deportation hearings – directives that would replace nearly all guidelines put in place by previous administrations.

"The surge of immigration at the southern border has overwhelmed federal agencies and resources and has created a significant national security vulnerability to the United States," Secretary Kelly wrote, citing a surge of 10,000 to 15,000 additional apprehensions per month at the US-Mexico border between 2015 and 2016.

Since taking office in January, President Trump has come under fire for what immigrant rights advocates have denounced as unprecedented action against undocumented people in the United States. In a series of executive orders last month, the president expanded the power of immigration officers and announced plans to fulfill his campaign promises by building a wall along the southern US border.

Raids in early February, in which Immigration and Customs Enforcement agents (ICE) rounded up more than 680 people in nearly a dozen states, spurred widespread fear across immigrant communities.

But the Trump administration's raids were actually smaller than similar sweeps under President Barack Obama, as The Christian Science Monitor's Harry Bruinius reported Tuesday. The Obama administration’s nationwide "Cross Check" operations apprehended more than 2,000 "convicted criminal aliens who pose the greatest risk to our public safety" in a similar five-day sweep in 2015.

At the time, officials said that ICE had arrested a total of 13,214 people in a total of six raids, information that a Trump administration fact sheet reiterated this week. As Mr. Bruinius reported for the Monitor:

By including this context in its fact sheets, and emphasizing that 75 percent of the immigrants detained last week had some kind of criminal conviction, the Trump administration emphasized continuity. After all, President Obama also prioritized the most dangerous undocumented criminals... Still, the enforcement actions created alarm in many communities – even a sense of panic as word spread that ICE agents were showing up at homes and making targeted arrests. In one sense, the unease was disproportionate to the size of the operation. But many legal experts and immigration advocates note that Mr. Trump’s executive orders on immigration – which call for the hiring of 10,000 additional immigration officers – have fundamentally changed the agency’s previous priorities. That sets the stage for what could be a much wider-ranging routine of targeting undocumented immigrants for arrest.

Defenders of Mr. Trump point to the Obama administration's record of having deported more people than any other White House in history, and argue that outrage over Trump's approach is hypocritical.

"With Trump now residing in the White House and Republicans building their agenda in Congress, activists will turn their attention to the narrative," wrote Austin Yack for National Review on Friday. "There is a new outpouring of articles on the deportation of illegal immigrants not because the press suddenly has a profound interest in the deportation of illegal immigrants, but because radicals who wish to erase our borders see an opportunity to demonize Trump and exploit his shortcomings for their agenda."

One significant change, immigrant rights activists note, is the Trump administration's definition of who is a "criminal." Trump's immigration order focuses not just on immigrants convicted of crimes, but anyone charged with an offense. Furthermore, it allows agents to arrest any person that an immigration officer perceives as posing a risk to either public safety or national security.

With the new guidelines signed Saturday, the Trump administration would further distance itself from previous administrations on immigration policy. The new directives would allow authorities to seek expedited deportation proceedings, which are currently limited to undocumented immigrants who have been in the country for two weeks or less, to anyone who has been in the country for up to two years. They would also immediately return Mexican immigrants who are apprehended at the border back home pending the outcomes of their deportation hearings instead of housing them on US property.

The memos also address the roughly 155,000 unaccompanied minors who have come from Mexico and Central America over the past three years. Under Kelly's guidelines, parents of these minors could be prosecuted if they are found to have paid smugglers to bring their children across the border.

Immigrants rights advocates were quick to condemn the new policies.

"[D]ue process, human decency, and common sense are treated as inconvenient obstacles on the path to mass deportation," said Joanne Lin, senior legislative counsel at the American Civil Liberties Union, in a statement. "The Trump administration is intent on inflicting cruelty on millions of immigrant families across the country."

In the memos, Kelly instructed agency chiefs to start hiring 10,000 additional ICE agents and 5,000 more for the Border Patrol, measures that were included in Trump’s executive actions last month. The DHS Secretary also expressed a desire to revive 287(g), a program introduced by former President Clinton that fell out of favor under the Obama administration, which would deputize local police to act as immigration officers for the purposes of enforcement. According to the memo, 32 jurisdictions in 16 states currently participate in the program.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

Missing from the memos was any action regarding the Deferred Action for Childhood Arrivals (DACA) program, which has provided work permits to more than 750,000 immigrants who entered the country illegally as children. During his campaign, Trump vowed to "immediately terminate" the program, but his stance appears to have softened since. Last week, he said he would "show great heart" in his approach.

The memos are currently under review by the White House Counsel's Office, which is reportedly seeking some changes.