The continuing protests in St. Louis over the shooting death of a young black man offer a stark reminder that whoever replaces Eric Holder as attorney general will arrive at the Justice Department at a unique moment for the agency's civil rights and criminal justice work. While the department over the past 13 years has been preoccupied with terrorism and Wall Street's infractions, the next attorney general's tenure could well be shaped by confronting the legacy of racism in America.

Holder often spoke loudly on these issues, saying what President Obama decided he could not, but his successor will have to wrestle with a complex array of issues. Racial tension over the police shooting of an unarmed teen in Ferguson, Mo., awakened this summer national concern about the makeup of local police departments and the bias and behavior of officers.

States have recently passed an array of new voting laws, from mandates to obtain a voter ID to limits on early voting, that raise civil-rights red flags as well. In confronting these new regulations, the DOJ now must respond without the power of a key provision of the Voting Rights Act that was dismantled last year by the Supreme Court.

Seismic changes are also underway in how the DOJ approaches sentencing guidelines and the war on drugs, which have long driven the unmatched rise of incarceration in America, and the parallel surge in costs particularly for minority communities. As a result of a shift in thinking about the goals of prison policy (and the effectiveness of the war on drugs), the federal prison population is now declining for the first time in three decades, a trend prison-reform groups are anxious to see continue.

For all of these reasons, criminal-justice and civil-rights advocates are counting on another vocal leader to replace Holder. They are looking for someone who will prioritize those roles of DOJ's mission — policing discrimination, protecting voting rights, redirecting prison policy — which have been periodically neglected, deemed outdated, or unwise.

The intensity with which these issues remain in the news, however, will complicate the confirmation process for Obama's nominee. It's harder today than just a few years ago to dismiss the persistence of racial bias in the criminal justice system, a topic that may be easier to openly acknowledge post-Ferguson. But there remains far less (if any) political agreement on the racial impacts of new voting laws.

"If you say at your confirmation hearings 'we’re going to spend a lot of time and effort on looking at these [state] statues that seem to restrict voting,' the Republicans are going to go crazy on that. Just crazy," says Richard Ugelow, a former longtime attorney in the Civil Rights Division of the DOJ and now a member of the faculty at American University's Washington College of Law.

Part of the department's challenge in its civil-rights work is that broad public disagreement over whether discrimination still exists has widened as discrimination itself has taken on subtler forms. Government agencies no longer openly bar minority job applicants. But recruiting practices may still have the effect of excluding them. Landlords no longer advertise when blacks aren't welcome. But the housing options available to minorities are still constricted by the fewer possibilities shown to them by landlords and real estate agents.

Likewise, public schools are no longer segregated by policy. But housing patterns have the effect of making them so, exposing children to unequal education. And literal poll taxes no longer exist. But voter IDs have been likened to them even by federal judges.

Holder, in fact, gave an impassioned speech earlier this May articulating this kind of "subtle" discrimination that lingers in America. But this same subtlety has allowed the DOJ, under previous attorneys general, to de-emphasize civil rights entirely. This was particularly true during the George W. Bush administration, when few civil-rights lawyers were hired and few cases litigated.

"I give Eric Holder a lot of credit for trying to rebuild the Civil Rights Division, which was really decimated under [John] Ashcroft and company," says Ugelow, who left the department in 2002. "They’ve been working hard at doing that. That involves personnel and morale and a whole range of issues, changing the culture from not doing much to being vigorous enforcers of civil-rights laws. I would want somebody who would continue to do that in a non-partisan way."

It's unlikely that Obama would nominate an attorney general who would return to an earlier time of shunning such civil-rights work — or who would abandon voting-rights litigation already underway (and yielding results) in Texas, for instance. But the sheer breadth of new voting laws, from Texas to Wisconsin to Ohio and North Carolina, means that advocates are counting on a fierce defender of voting rights (even if the topic becomes touchy in confirmation).

"On voting, there's just tremendous turmoil and anxiety in communities of color and among young people and the elderly about voter ID, and about the Voting Rights Act itself," says Laura Murphy, the director of the ACLU Washington legislative office.

Concerns have grown since the 5-4 Supreme Court ruling last year — Shelby County v. Holder — that invalidated the formula embedded in the Voting Rights Act which identified states with a history of discrimination as requiring special scrutiny any time they change their voting laws. Without that provision, a new AG will confront new voting restrictions with fewer tools to challenge them (in the Texas case, the DOJ is trying to wield a different provision of the Voting Rights Act).

Murphy adds to her priorities for the next AG another long list of wants well beyond voting-rights enforcement: She'd like Holder's replacement to continue the department's work investigating excessive use of force by police departments, the conditions in jails and prisons, and the use of solitary confinement. She'd like Holder's replacement to support the Smarter Sentencing Act, which would reduce mandatory minimum sentences and extend the work already embraced by the DOJ of rolling back harsh and disproportionate sentences that emphasize locking people up over protecting communities or transitioning prisoners back into society.

The ACLU, among many organizations, has also long been waiting for the DOJ to issue new guidance on the use of race in law enforcement, updating policies that haven't been changed since 2003.

One week before announcing his resignation, Holder unveiled a final program relevant to many of these issues — and responding in particular to Ferguson — that his successor will have to take up: the National Initiative for Building Community Trust and Justice, a $4.75 million grant program to invest in five pilot communities on police training and local strategies that could ease distrust between police and residents. If that sounds like a PR campaign more than serious policy play, Nancy La Vigne, the director of the Urban Institute's Justice Policy Center, says "it's huge."

"He doesn’t do many grant announcements from his conference room," says La Vigne, who previously worked in the DOJ. "Nor have I seen anything in my time at DOJ like this consortium of support across DOJ agencies, that's about more than middle-level managers showing up at meetings, that's backed by real grant dollars. It's clear to me this is one of his legacy items."