When the Obama administration launched a sweeping policy to reduce harsh prison sentences for nonviolent drug offenders, rave reviews came from across the political spectrum. Civil rights groups and the Koch brothers praised Obama for his efforts, saying he was making the criminal justice system more humane.

But there was one person who watched these developments with some horror. Steven Cook, a former street cop who became a federal prosecutor based in Knoxville, Tennessee, saw nothing wrong with how the system worked - not the life sentences for drug charges, not the huge growth of the prison population. And he went everywhere - Bill O'Reilly's show on Fox News, congressional hearings, public panels - to spread a different gospel.

"The federal criminal justice system simply is not broken. In fact, it's working exactly as designed," Cook said at a criminal justice panel at The Washington Post last year.

The Obama administration largely ignored Cook, who was then president of the National Association of Assistant U.S. Attorneys. But he won't be overlooked anymore.

Attorney General Jeff Sessions has brought Cook into his inner circle at the Justice Department, appointing him to be one of his top lieutenants to help undo the criminal justice policies of Obama and former attorney general Eric Holder Jr. As Sessions has traveled to different cities to preach his tough-on-crime philosophy, Cook has been at his side.

Sessions has yet to announce specific policy changes, but Cook's new perch speaks volumes about where the Justice Department is headed.

Law enforcement officials say that Sessions and Cook are preparing a plan to prosecute more drug and gun cases and pursue mandatory minimum sentences. The two men are eager to bring back the national crime strategy of the 1980s and '90s from the peak of the drug war, an approach that had fallen out of favor in recent years as minority communities grappled with the effects of mass incarceration.

Crime is near historic lows in the United States, but Sessions says that the spike in homicides in several cities, including Chicago, is a harbinger of a "dangerous new trend" in America that requires a tough response.

"Our nation needs to say clearly once again that using drugs is bad," Sessions said to law enforcement officials in a speech in Richmond last month. "It will destroy your life."

Advocates of criminal justice reform argue that Sessions and Cook are going in the wrong direction - back to a strategy that tore apart families and sent low-level drug offenders, disproportionately minority citizens, to prison for long sentences.

"They are throwing decades of improved techniques and technologies out the window in favor of a failed approach," said Kevin Ring, president of Families Against Mandatory Minimums (FAMM).

But Cook, whose views are supported by other federal prosecutors, sees himself as a dedicated assistant U.S. attorney who for years has tried to protect neighborhoods ravaged by crime. He has called FAMM and organizations like it "anti-law enforcement groups."

The records of Cook and Sessions show that while others have grown eager in recent years to rework the criminal justice system, they have repeatedly fought to keep its toughest edges, including winning a battle in Congress last year to defeat a reform bill.

"If hard-line means that my focus is on protecting communities from violent felons and drug traffickers, then I'm guilty," Cook said in a recent interview with The Post. "I don't think that's hard-line. I think that's exactly what the American people expect of their Department of Justice."

When asked for a case that he was proud to work on during his three-decade career as a prosecutor, Cook points to when his office went after a crack ring operating in Chattanooga housing projects between 1989 and 1991.

This was during the height of the crack epidemic and the drug war. After the cocaine overdose of black basketball star Len Bias in 1986, Congress began passing "tough on crime" laws, including mandatory minimum sentences on certain drug and gun offenses. In 1994, President Bill Clinton signed one of the toughest-ever crime bills, which included a "three strikes" provision that gave mandatory life sentences for repeat offenders.

Federal prosecutors such as Cook applauded their "new tools" to get criminals off the street.

Cook said last year: "What we did, beginning in 1985, is put these laws to work. We started filling federal prisons with the worst of the worst. And what happened next is exactly what Congress said they wanted to happen - and that is violent crime began in 1991 to turn around. By 2014, we had cut it in half."

To bring down the Chattanooga drug ring's leader, Victor Novene, undercover federal agents purchased crack from Novene's underlings. Prosecutors then threatened them with long prison sentences to "flip" them to give up information about their superiors.

Cook said in March: "We made buys from individuals who were lower in the organization. We used the mandatory minimums to pressure them to cooperate."

Cook's office also added gun charges to make sentences even longer, another popular tool among prosecutors seeking the longest possible punishments.

With the mandatory minimum sentences and firearms "enhancements," Novene received six life sentences. Many of his lieutenants were sentenced to between 16 and 33 years in federal prison.

But sentencing reform advocates say the tough crime policies went too far. The nation began incarcerating people at a higher rate than any other country - jailing 25 percent of the world's prisoners at a cost of $80 billion a year. The nation's prison and jail population more than quadrupled from 500,000 in 1980 to 2.2 million in 2015, filled with mostly black men strapped with lengthy prison sentences - 10 or 20 years, sometimes life without parole for a first drug offense.

Obama, the first sitting president to visit a federal prison, launched an ambitious clemency initiative to release certain drug offenders from prison early. And Holder told his prosecutors, in an effort to make punishments more fairly fit the crime, to stop charging low-level nonviolent drug offenders with offenses that imposed severe mandatory sentences. He called his strategy, outlined in an August 2013 report, "Smart on Crime."

Cook has called it "Soft on Crime" and said the Chattanooga case would have been much more difficult to make, "if possible at all," in recent years.

"We were discouraged from using mandatory minimums," Cook said about Holder's 2013 charging and sentencing memo to prosecutors. "The charging memo handcuffed prosecutors. And it limited when enhancements can be used to increase penalties, an important leverage when you're dealing with a career offender in getting them to cooperate."

Cook has also dismissed the idea that there is such a thing as a nonviolent drug offender.

"Drug trafficking is inherently violent. Drug traffickers are dealing in a heavy cash business," he said on the "O'Reilly Factor" last year. "They can't resolve disputes in court. They resolve the disputes on the street, and they resolve them through violence."

Cook and Sessions have also fought the winds of change on Capitol Hill, where a bipartisan group of lawmakers recently tried but failed to pass the first significant bill on criminal justice reform in decades.

The legislation, which had 37 sponsors in the Senate, including Sen. Charles Grassley, R-Iowa, and Mike Lee, R-Utah, and 79 members of the House, would have reduced some of the long mandatory minimum sentences for gun and drug crimes. It also would have given judges more flexibility in drug sentencing and made retroactive the law that reduced the large disparity between sentencing for crack cocaine and powder cocaine.

The bill, introduced in 2015, had support from outside groups as diverse as the Koch brothers and the NAACP. House Speaker Paul Ryan, R-Wis., supported it, as well.

But then people such as Sessions and Cook spoke up. The longtime Republican senator from Alabama became a leading opponent, citing the spike in crime in several cities.

"Violent crime and murders have increased across the country at almost alarming rates in some areas. Drug use and overdoses are occurring and dramatically increasing," said Sessions, one of five members of the Senate Judiciary Committee who voted against the legislation. "It is against this backdrop that we are considering a bill . . . to cut prison sentences for drug traffickers and even other violent criminals, including those currently in federal prison."

Cook testified that it was the "wrong time to weaken the last tools available to federal prosecutors and law enforcement agents."

After GOP lawmakers became nervous about passing legislation that might seem soft on crime, Senate Majority Leader Mitch McConnell, R-Ky., declined to bring the bill to the floor for a vote.

"Sessions was the main reason that bill didn't pass," said Inimai Chettiar, the director of the Justice Program at the Brennan Center for Justice. "He came in at the last minute and really torpedoed the bipartisan effort."

Now that he is attorney general, Sessions has signaled a new direction. As his first step, Sessions told his prosecutors in a memo last month to begin using "every tool we have" - language that evoked the strategy from the drug war of loading up charges to lengthen sentences.

And he quickly appointed Cook to be a senior official on the attorney general's task force on crime reduction and public safety, which was created following a Trump executive order to address what the president has called "American carnage."

"If there was a flickering candle of hope that remained for sentencing reform, Cook's appointment was a fire hose," said Ring, of FAMM. "There simply aren't enough backhoes to build all the prisons it would take to realize Steve Cook's vision for America."

Sessions is also expected to take a harder line on the punishment for using and distributing marijuana, a drug he has long abhorred. His crime task force will review existing marijuana policy, according to a memo he wrote prosecutors this week. Using or distributing marijuana is illegal under federal law, which classifies it as a Schedule 1 drug, the same category as heroin, and considered more dangerous than cocaine and methamphetamine.

In his effort to resurrect the practices of the drug war, it is still unclear what Sessions will do about the wave of states that have legalized marijuana in recent years. Eight states and the District of Columbia now permit the recreational use of marijuana, and 28 states and the District have legalized the use of medical marijuana.

But his rhetoric against weed seems to get stronger with each speech. In Richmond, he cast doubt on the use of medical marijuana and said it "has been hyped, maybe too much."

Sessions's aides stress that the attorney general does not want to completely upend every aspect of criminal justice policy.

"We are not just sweeping away everything that has come before us." said Robyn Thiemann, the deputy assistant attorney general in the Office of Legal Policy, who is working with Cook and has been at the Justice Department for nearly 20 years. "The attorney general recognizes that there is good work out there."

Still, Sessions's remarks on the road reveal his continued fascination with an earlier era of crime fighting.

In the speech in Richmond, he said, "Psychologically, politically, morally, we need to say - as Nancy Reagan said - 'Just say no.' "

(c) 2017, The Washington Post. Sari Horwitz wrote this story.