Washington (CNN) The future of criminal justice reform hangs in the balance as the nomination of Alabama Sen. Jeff Sessions, President Donald Trump's pick for attorney general, was advanced in a party-line vote by the Senate Judiciary Committee Wednesday.

Activists worry that Trump, who preached "law and order" during his campaign and threatened last week to "send in the Feds" to violence-plagued Chicago, would halt former President Barack Obama's reforms, and institute new policies that could worsen conditions.

"The Republican Party right now is divided between people who recognize now that the criminal justice system is a big failed, unaccountable government bureaucracy that's wasting money and lives on the one hand," CNN political commentator Van Jones told CNN. "On the other hand, you have people who want to stick with the same old dumb on crime, lock 'em up policies that have made things worse, not better. Where Trump comes down is not clear yet."

Trump is expected to move ahead with an executive action this week addressing local crime-fighting and curbing the sale of drugs in the United States.

Here's why activists and civil rights groups fear Trump's White House could turn a deaf ear to racial biases in law enforcement and policing:

Sessions' record on sentencing reform disputed

Trump's nomination of Sessions to be the next attorney general has exacerbated concerns that policing and sentencing reforms initiated by Obama would come to an end.

As President, Obama granted 1,715 commutations for non-violent drug offenders -- more than the past 12 presidents combined. Of those, 568 of the individuals who received lesser sentences had been sentenced to death.

Sessions slammed Obama's efforts as a "weakening of some of our most important criminal sentencing policies."

As a candidate, Trump accused the Obama White House of giving "drug dealers and gang members" a "slap on the wrist" and turning them "loose on the street."

The American Civil Liberties Union, a strong advocate for criminal justice reform, wrote a letter last week urging leadership of the Senate Judiciary Committee to hold a second hearing and cancel the vote on the senator's nomination.

During his confirmation hearing earlier this month Sessions was met by strong opposition from Senate Democrats, most notably New Jersey Sen. Cory Booker, who became the first sitting senator to testify against a fellow sitting senator at a confirmation hearing for a Cabinet position.

Booker slammed Sessions during the hearing, specifically citing his concern with his colleague's voting record on "the crisis of mass incarceration."

"His record indicates that at a time when even the FBI director is speaking out about implicit racial bias in policing and the need to address it; at a time when the last two attorneys general have taken steps to fix our broken criminal justice system ... Sen. Sessions would not continue to lead urgently needed change," Booker said.

JUST WATCHED Cory Booker testifies against Sessions Replay More Videos ... MUST WATCH Cory Booker testifies against Sessions 02:48

"America needs an Attorney General who is resolute and determined to bend the arc. Senator Sessions' record does not speak to that desire, intention, or will," he added.

But former deputy attorney general Larry Thompson defended Sessions at the hearing and applauded his bipartisan work with Sen. Dick Durbin in passing the 2010 Fair Sentencing Act , which reduced the sentencing disparity between offenses for crack and powder cocaine from 100:1 to 18:1.

"Sen. Sessions would vigorously, but impartially enforce our laws," Thompson said. "Of all our important civil rights, the rights to be safe and secure in one's home and neighborhood is perhaps the most important," he added.

The ACLU said that while the Fair Sentencing Act was a "a step toward fairness," the law "still reflects outdated and discredited assumptions about crack cocaine."

Sessions defended his record on criminal justice reform while being questioned by Durbin during the hearing and referenced a similar 2001 bill he co-sponsored, which was then criticized by the Bush administration.

"I stepped out against my own Republican administration and said openly on the floor of the Senate that I believed these crack cocaine laws were too harsh," Sessions said, "and it was disadvantageous to the African-American community where most of the punishments were falling."

Sessions dogged by old allegations of racism

Sessions' nomination has also been dogged by old allegations of racism, which stem from racially charged comments he allegedly made as a US attorney in Alabama, which led him to be denied a federal judgeship 30 years ago.

While the ACLU says they do not take a position supporting or opposing judicial nominations, the group has contested Sessions' position on civil rights issues.

During Sessions' confirmation hearing the ACLU's legal director David Cole urged lawmakers to consider the Senator's record on civil rights — namely his opposition to the 1964 Voting Rights Act.

Sessions defended himself against accusations of racism at the hearing and said he was unfairly portrayed as a racist in the past.

"I didn't prepare myself well in 1986 and there was an organized effort to caricature me as something that wasn't true," he said. "I hope my tenure in this body has shown you that the caricature that was created of me was not accurate," he added.

JUST WATCHED RECAP: Jeff Sessions confirmation hearing (Day 1) Replay More Videos ... MUST WATCH RECAP: Jeff Sessions confirmation hearing (Day 1) 02:52

And William Smith, a longtime Sessions staffer, defended the senator's record at the hearing, saying, "After 20 years of knowing Sen. Sessions, I have not seen the slightest evidence of racism because it does not exist."

But the NAACP, which vehemently opposes Sessions as attorney general, issued an action alert for supporters Wednesday, urging them to contact their lawmakers and oppose Sessions.

"Sen. Sessions as AG is deeply troubling, and supports an old, ugly history where Civil Rights were not regarded as core American values," the NAACP tweeted.

Sessions previously called the ACLU and the NAACP "un-American" and said these organizations "forced civil rights down the throats of people."

Trump supports stop-and-frisk tactics

Throughout the 2016 campaign Trump argued repeatedly that stop-and-frisk policies reduced crime in New York City and in September, he called for implementing these controversial policies in Chicago.

A US District Court judge ruled in 2013 that New York City's use of stop-and-frisk is unconstitutional because it violates the Fourth Amendment and has been used to target people based on race.

New York City Mayor Bill de Blasio disputed Trump's claim that the practice led to a reduction of crime.

"With stop-and-frisk down nearly 97% from its high point in 2011, crime in New York City is now at record lows," de Blasio wrote in a September op-ed for CNN

"Stop-and-frisk was not a driver of that public safety progress. Donald Trump's refusal to admit this and his willingness to inflame tensions for political purposes isn't just foolish. It's dangerous," he added.

Despite the tactic being ruled unconstitutional, Trump insisted that stop-and-frisk is "constitutional" during the first presidential debate and said that implementing it in Chicago would "overwhelmingly" save African-American and Hispanic lives.

Sessions later agreed with Trump, telling Bustle, "It's all about how that is done."

The role of police reform

Over the past two years, Obama-appointed Attorney General Loretta Lynch launched several Justice Department investigations into police departments around the nation, including Ferguson Baltimore and Chicago , revealing patterns of racial discrimination in policing and cases of excessive force.

In some cases, the Obama White House has used consent decrees to make changes in policing, which require the city to implement reforms under court supervision, whether the police department agrees with the findings or not.

Whether a Trump administration will act to address these findings, open new investigations or utilize consent degrees is yet to be seen.

Sessions suggested during his confirmation hearing that as attorney general he could move the Justice Department away from the use of consent decrees, saying that police departments "often feel forced to agree to a consent decree just to remove that stigma and sometimes there are difficulties there."

Trump criticized the federal government's interference in state policing as a candidate and said that law enforcement should be "a local or state issue."

"Most law enforcement is local in nature and should be dealt with accordingly. If the federal government can provide assistance in facilitating stronger community relationships, then the Trump administration will be there to assist. Otherwise, state and local authorities must answer to their own constituencies," Trump wrote in response to a question from the International Association of Chiefs of Police on how he would work to improve relations between communities and the police.

Sessions also accused the Obama White House of politicizing the issue.

JUST WATCHED Donald Trump on the 'Black Lives Matter' movement Replay More Videos ... MUST WATCH Donald Trump on the 'Black Lives Matter' movement 01:34

"There is a perception, not altogether unjustified, that this department and the Civil Rights Division goes beyond fair and balanced treatment. ... That's been a troubling issue for a number of years, frankly," Sessions said during a Judiciary Senate Committee hearing in November 2015.

Trump slammed the "Black Lives Matter" movement as a candidate, lamented a "war on police," and accused the group of helping to instigate police shootings through their protests and rallies against police brutality.

When asked in July if he would investigate "Black Lives Matter" as president, Trump suggested that his attorney general would "do something."

"We are going to have to, perhaps, talk to the attorney general about it or do something," he said.

In a statement released following Trump's election, the Black Lives Matter movement, called on people to organize: "Donald Trump has promised more death, disenfranchisement and deportations. We believe him. The violence he will inflict in office, and the permission he gives for others to commit violence, is just beginning to emerge. In the face of this, our commitment remains the same: protect ourselves and our communities."