WASHINGTON >> When William Barr was attorney general in the early 1990s, he was outspoken about some of America’s biggest problems — violent crime, drug addiction, teenage pregnancy. The “Age of Aquarius,” he warned, had given way to crack babies and broken families, misery and squalor.

The rhetoric reflected Barr’s deep-seated personal beliefs and was typical talk for a conservative Republican at a time when family values and tough-on-crime stances defined the party.

Now, as President Donald Trump’s nominee for attorney general, Barr is poised to return to the same job in a dramatically different Washington.

Republicans just pushed through the biggest criminal justice overhaul in a generation, easing prison sentences. Family-values are seldom discussed while Trump, twice-divorced and accused of affairs and sexual misconduct, sits in the White House. Serving Trump, who faces intensifying investigations from the department Barr would lead, is unlikely to compare with his tenure under President George H.W. Bush.

Trump demands loyalty, breaking with the practice of shielding law enforcement from political influence. He publicly browbeats Justice Department leadership and ousted his first attorney general, Jeff Sessions, for not protecting him in the Russia investigation. Though the pressures on Barr are bound to be enormous if he is confirmed, allies describe him as driven by his commitment to the department and clear-eyed about what is ahead.

“I have no doubt that he’s aware of any unique or unusual challenges that this Justice Department, his Justice Department, will confront,” said longtime friend and former colleague Chuck Cooper, who is also Sessions’ lawyer. “He approaches these challenges as a public servant who loves his country and who’s answering the call to service. That’s the spirit in which Bill Barr is accepting these challenges.”

The first challenge comes Tuesday when Democrats press him at his Senate Judiciary Committee hearing on his broad views of presidential power, including an unsolicited memo he sent the Justice Department last year criticizing special counsel Robert Mueller’s investigation into whether the president had sought to obstruct the Russia investigation.

Barr is likely to win confirmation and, given his past experience, probably won’t face challenges over his qualifications the way other Trump nominees have. Republicans control the Senate and could pick up some support from Democrats eager for the departure of acting Attorney General Matthew Whitaker. Democrats wanted Whitaker to step aside from overseeing Mueller’s investigation into links between Russia and the Trump campaign, citing Whitaker’s criticism of the inquiry before he joined the department.

Barr would inherit that investigation as it reaches critical decisions and as Mueller’s most prominent protector inside the department, Deputy Attorney General Rod Rosenstein, expects to depart.

Though Barr’s handling of the investigation is the most pressing issue confronting him, equally important will be stabilizing a department riven by leadership tumult — as well as his own dynamic with Trump.

Though both Trump and Barr are plain-spoken native New Yorkers and generational contemporaries, the two appear to have little in common.

Barr, 68, is a practicing Catholic and longtime creature of Washington — a CIA alumnus who climbed the Justice Department ranks, associated with establishment figures long maligned by Trump and delivered legal reasoning behind some of the most consequential actions of the time, including the invasion of Panama.

Even if Barr doesn’t introduce sweeping policy changes, he might nonetheless have to adjust to the shifting winds of the White House or fellow Republicans on Capitol Hill.

The administration, for instance, recently backed legislation reducing mandatory minimum punishments and giving judges more discretion when sentencing some drug offenders.

Barr will reassure lawmakers that he supports the law, according to a person close to the confirmation process who spoke on condition of anonymity to discuss private conversations. That’s a striking departure from Barr’s insistence as attorney general, in the face of homicide rates that dwarf today’s totals, that “we are not punitive enough” about violent crime.

Recipients of mandatory minimum sentences richly deserve them, he once said, denouncing as a myth the notion sympathetic and “hapless victims of the criminal-justice system” are languishing in prison longer than they deserve.

Barr’s pro-law enforcement stance is so entrenched, one friend said, that as a Columbia University student in the 1960s he brought police coffee as they encountered protesters.

“He’s very much a law-and-order guy. He believes the primary responsibility of government is to maintain the security of its citizens,” said longtime friend Andrew G. McBride, a former Justice Department colleague.

As attorney general, Barr connected violent crime to a “moral crisis” in society, decrying high rates of divorce and drug addiction, and rising secularism that he said prevented children from discerning right from wrong.

“The prophets of the sexual revolution and the drug culture proclaimed the dawn of a new era of maturity and freedom, of peace and love,” he said at a 1992 Chicago event. “That’s not what happened — not by a long shot. Today we can see the grim harvest of the Age of Aquarius: Broken families, venereal diseases, teenage pregnancies, crack babies. We see misery and squalor, confusion and loneliness.”

In speeches, he repeatedly mocked Woody Allen’s justification — “The heart wants what it wants” — for his relationship with partner Mia Farrow’s adopted daughter.

Try that rationale, he said, “as a foundation for any sort of human behavior and you will see at once the danger and moral corruption it entails.”

The perspective could create an awkward coexistence with a president known for misstatements and embellishments and who, prosecutors say, directed hush money payments to cover up claims of extramarital relationships with two women.

It’s not clear how often he and Trump will interact and under what circumstances. Friends insist he won’t easily bend to the president’s will, describing Barr as principled, smart and strong-willed.

“Bill is not a shrinking violet,” said former colleague Timothy Flanigan. “Bill is tough, tough in a good way.”

Barr didn’t campaign for the job and even proposed other names to the White House instead of his own, one friend. Returning as attorney general to stabilize the department could be a career capstone of sorts.

“He can take this without worrying about career advancement,” said C. Boyden Gray, White House counsel to George H.W. Bush. “If he were a lot younger, I’m not sure he would have done it.”