By Julia Edwards and Roberta Rampton

WASHINGTON, Sept 25 (Reuters) – The departure of U.S. Attorney General Eric Holder deprives the Obama administration of a powerful voice on civil rights at a time when riots in Ferguson, Missouri, have thrust the issue into the spotlight.

Civil rights advocates fear his exit leaves a hard-to-fill hole on Obama’s team when it comes to events such as in Ferguson – where days of protests followed the fatal police shooting of an unarmed black teenager – and challenging laws in some states requiring voters to show photo identification, measures that Holder has said would prevent black and Latino voters from going to the polls.

They are worried that his work on voting rights, sentencing reform, and addressing racial profiling measures used by police could fall by the wayside when his yet-to-be-determined successor sets a new set of priorities – particularly as the administration focuses on counterterrorism and the threat posed by Islamic State militants.

“We always thought that he was able to say the things that Obama could not say,” said Barbara Arnwine, president of the Lawyers’ Committee for Civil Rights.

“We’ve always seen him as an important spokesperson for the administration and that role should not go unfulfilled.”

BONDS THAT GO ‘MUCH DEEPER’

In a speech choked with emotion on Thursday, Holder recounted how he had been part of Team Obama since his friend was a “young senator from Illinois” making “an improbable, idealistic effort” to become president.

Obama stuck with Holder even as he became a lightning rod for Republican criticism of his administration.

“We have been great colleagues, but the bonds between us are much deeper than that. In good times and in bad, in things personal and in things professional, you have been there for me,” Holder said to Obama.

Over the years, both men have spoken about racism they have experienced in their own lives.

Before he became the nation’s first black president, Obama wrote “Dreams from My Father,” a memoir on racial identity. But since taking office, he has often shied away from talking publicly about race.

By contrast, Holder – who worked for the NAACP legal defense fund early in his career – has been more outspoken. His sister-in-law, Vivian Malone Jones, became a hero in the desegregation movement of the 1960s after she was blocked from entering the University of Alabama when she arrived for classes.

“I think in his own way, using his role as Attorney General, Holder has addressed issues that remain off-limits,” said Wade Henderson, president of the Leadership Conference on Civil and Human Rights.

Holder talked openly about his own experiences with racial profiling after Trayvon Martin, a black teenager in Florida, was shot last year – days before Obama spoke out.

Holder talked about the humiliation of being pulled over and searched on the New Jersey turnpike when he was not speeding, and about being stopped by police while running in Washington’s tony Georgetown neighborhood.

In August, after unarmed black teenager Michael Brown was shot and killed by a white policeman in Ferguson – sparking nights of riots – Obama sent Holder to meet with community members.

Holder vowed the Justice Department would investigate whether criminal and civil charges are warranted, but the probe is unlikely to be complete before his departure.

THINGS LEFT UNDONE

As he listed his accomplishments, Holder acknowledged that “work remains to be done.”

On his to-do list in the weeks before he leaves, Holder hopes to announce new guidelines to curb racial profiling in federal law enforcement investigations, the Justice Department said.

Holder has asked federal prosecutors not to seek mandatory minimum sentences to be used when charging defendants in low-level drug cases. But more sweeping proposals to abolish mandatory minimum sentences have failed to get traction in Congress.

Holder announced earlier this year that the department would review potentially hundreds of applications for executive clemency – another project that is under way but unfinished.

In his farewell speech, Holder highlighted how he and Obama have “fought to protect the most sacred of American rights: the right to vote.”

He challenged state voting laws in Texas and North Carolina that he said would restrict voting by blacks and Latinos.

“I hope that his successor continues vigorous enforcement of the Voting Rights Act,” said Laura Murphy, director of the Washington legislative office for the American Civil Liberties Union. (Reporting by Roberta Rampton and Julia Edwards; Editing by Ken Wills)