President-elect Donald Trump has nominated US Senator Jeff Sessions of Alabama to be his administration's attorney general, a move that civil liberties advocates are decrying as a likely catastrophe for privacy and immigration.

While many of Trump’s forthcoming nominations will amount to little more than inside-the-Beltway gossip, Sessions stands out. He's an advocate for surveillance and an enemy of encryption; an opponent of criminal justice reform; and a hardliner on immigration. First elected to the US Senate in 1996, he has long stood to the right even among his conservative Republican colleagues as a champion of security above all. As Attorney General, Sessions would have the power to radically recast the Obama administration’s definition of civil liberties online and off.

The Senate Judiciary Committee must still approve Sessions' nomination. But civil rights groups are already sounding the alarm over the possibility that he could become the most powerful law enforcement officer in the land. Sessions' track record also suggest he's also going to find himself at sharp odds with the tech industry’s liberal and libertarian-leaning leadership.

The Anti-Immigration Crusader

Sessions has been perhaps the most influential figure in shaping Trump’s sweeping immigration policy. The president-elect has promised to build a border wall, deport millions of undocumented immigrants, repeal a program that defers deportation of people who came to the United States as kids, and impose severe limits on the immigration of high-skilled workers. Sessions has championed all of these positions throughout his nearly 20 years in office. At the crux of Sessions' argument is that immigration, both legal and illegal, threatens Americans' physical security—and their job security.

“He’s never seen a visa program he wouldn’t like to take away,” says Ali Noorani, executive director of the National Immigration Forum, which advocates for immigration reform. “He is opposed to immigration as we know it. Full stop.”

This has put Sessions at odds with the tech industry’s pro-immigration advocates, including Mark Zuckerberg. In 2014, when the Zuckerberg-backed lobbying group FWD.us was funding ads in support of a comprehensive immigration reform bill, Sessions personally denounced Zuckerberg in a lengthy speech on the Senate floor.

“So I would pose a question to Mr. Zuckerberg,” Sessions said at the time. “I read in the news that Facebook is now worth more than $200 billion. Is that not enough money to hire American workers for a change?”

FWD.us declined to comment for this story, but in an interview in April, executive director Todd Schulte said of Sessions, “It’s very hard to make the case he’s not the single worst person on high-skilled immigration.”

In fact, during a campaign stop in Iowa in October, Sessions went so far as to suggest getting rid of the so-called H1-B program altogether. “I don't think the republic would collapse if it was totally eliminated,” he said.

Immigration advocates like Noorani worry more about the wider swath of immigrants facing deportation under a Trump administration. The president-elect has said he would start by deporting three million criminals who are undocumented. Activists worry that Sessions’ definition of a criminal may be overly broad.

A Threat to Privacy

When it comes to the attorney general’s role of limiting law enforcement and intelligence agencies’ surveillance powers, privacy advocates say Sessions’ appointment represents a nightmare scenario. The senator has repeatedly worked to block NSA privacy reforms, sided with the FBI in its standoff with Apple over the iPhone’s encryption, and pushed legislation that would force technology companies to turn over private information to law enforcement.

Robyn Greene, policy counsel at the New America Foundation’s Open Technology Institute, says Sessions is a dangerous choice for the role of enforcing legal limits on intelligence agencies like the NSA. “Unless Congress picks up the mantle of aggressive oversight of the intelligence community, we’re looking at a situation that makes the Hoover era looks like child’s play," Green says.

In his nearly two decades as a senator, Sessions has pushed for spying powers beyond even those supported by his Republican congressional colleagues and intelligence agents. He fought reform of the Foreign Intelligence Surveillance Act in 2012 and against the USA Freedom Act that in 2015 placed new limits the NSA’s spying powers after the revelations of Edward Snowden—a law that passed a Republican House and Senate and was even endorsed by NSA director Michael Rogers.

“When it comes to surveillance powers, he’s more catholic than the Pope,” says privacy-focused Cato Institute fellow Julian Sanchez. “He wants to grant more authorities with fewer limitations than even the law enforcement or intelligence communities are asking for.”

But Sessions’ most privacy-invasive move as senator may have been his attempt to add an amendment to the Email Privacy Act, a bill passed in the Republican-controlled House of Representatives in May designed to require a warrant for law enforcement to compel tech firms like Google and Microsoft to hand over Americans’ stored communications. Sessions’ amendment would create a loophole that would allow law enforcement to demand data without a warrant in ill-defined “emergency” cases—never mind that companies already routinely hand over user data without being compelled in legitimate emergencies. Even James Trainium, a former homicide detective, wrote in an editorial that the emergency exception measure is “unwise and unsafe.”

A Brave New World for Law Enforcement

Government surveillance has been particularly problematic for leaders of the Black Lives Matter movement, whom the FBI and other law enforcement agencies have spied on in recent years, using everything from camera-equipped drones to social media surveillance tools like Geofeedia.

Now, civil rights groups worry that with Sessions as the nation's most powerful law enforcer, the already strained relationship between communities of color and law enforcement is bound to get even worse.

Sessions has been an outspoken opponent of bipartisan efforts to shrink the country's massive prison and jail system. He was one of only a handful of senators standing in the way of the Sentencing Reform and Corrections Act, which would, among other things reduce mandatory minimum sentences—a measure that enjoyed support from Republican leaders like House Speaker Paul Ryan. Once again, Sessions made the case for security, arguing that reducing mandatory minimums for drug offenders would "release thousands of violent felons and endanger millions of Americans whose safety is increasingly threatened by rising crime rates."

But Sessions' issues with communities of color do not start or end with his stance on criminal justice reform. In the 1980s, the senator was blocked from federal judgeship after a fellow attorney testified Sessions had made racially insensitive remarks to him. Another witness testified that Sessions had made remarks that were sympathetic to the Ku Klux Klan.

In response to questions about Sessions' alleged racism, Trump spokesman Jason Miller said the senator is "universally respected across party lines." Miller noted that as US attorney, Sessions filed desegregation lawsuits. As a senator, he supported Eric Holder's appointment to attorney general under President Obama and awarded Rosa Parks a Congressional Gold Medal.

But civil rights groups like the NAACP have little faith that Sessions will continue the criminal justice reform efforts undertaken by Holder and current Attorney General Loretta Lynch. At a time of great discord between black Americans and law enforcement, the current Justice Department has opened investigations into the police shooting of Michael Brown in Ferguson, Missouri, and the death of Freddie Gray in Baltimore after being injured in police custody. A Sessions-run Justice Department—driven by a credo of security above all else—may not have the same priorities.

It's too early to tell, of course, how much input Sessions would have in a Trump administration to dictate these policies. On a call about the nomination, Sean Spicer, the RNC's chief strategist and communications director, told reporters, "Everybody who serves under Trump’s administration will serve Donald Trump and Mike Pence, and they will implement that vision and their ideas and no one else’s."

Given how close Sessions and Trump have been throughout the last year, it seems those visions aren't too far apart.