A report released Tuesday by the Justice Department’s inspector general found the department’s voting rights section mired in deep ideological polarization and distrust, in some cases harming its ability to function over the past two administrations.

The 258-page review by Inspector General Michael E. Horowitz found “numerous and troubling examples of harassment and marginalization of employees and managers.” The unprofessional behavior included racist and other inappropriate e-mails, Internet postings, blogs, and personal attacks by voting rights lawyers and staffers.

The report found no evidence that enforcement decisions were made in the George W. Bush administration or the Obama administration based on race or partisan considerations. Among its responsibilities, the voting section reviews redistricting cases that can change the composition of congressional districts and voter ID laws that affect who is eligible to cast a ballot.

The findings could present problems for Thomas E. Perez, the assistant attorney general for civil rights, who is likely to be President Obama’s nominee for labor secretary. The Civil Rights Division oversees the voting section.

Several e-mails and Internet postings described in the report illustrated the contentious atmosphere in the voting section. In one, an employee characterized the neighborhood of a conservative career lawyer as a place where “everyone wears a white sheet, the darkies say ‘yes’m’ and equal rights for all are the real ‘land of make believe.’ ” Another post by a career employee said that “a good, ethical Republican” is a “seeming oxymoron.” One posting used the expression “po’ Niggrahs” to describe a manager’s attitude toward African Americans.

In a letter to the inspector general, Perez said he has tried to improve the professionalism of a section that, when he inherited it in the fall of 2009, had “low morale” and an “unacceptable degree of staff conflict.” The report said the racist postings were made before Perez arrived.

“Since 2009, the Civil Rights Division and the Voting Section have undertaken a number of steps to improve the professionalism of our workplace and to ensure that we enforce the civil rights law in an independent, evenhanded fashion,” Perez wrote in his response.

Nancy Zirkin, executive vice president of the Leadership Conference on Civil and Human Rights, said the report shows that Perez has ended politicized hiring practices and enforcement decisions. “Today’s report shows . . . that Assistant Attorney General Tom Perez has restored integrity to the Civil Rights Division and its Voting Section,” Zirkin said in a statement.

But Rep. Frank R. Wolf (Va.), one of the Republican lawmakers who called for an investigation of a case handled by the voting section, said he was deeply troubled by the findings.

“The report makes clear that the division has become a rat’s nest of unacceptable and unprofessional actions, and even outright threats against career attorneys and systemic mismanagement,” Wolf said in a statement.

The investigation of the section started after Wolf and Rep. Lamar Smith (R-Tex.) sent letters to the inspector general questioning the department’s handling of a case involving the New Black Panther Party. On Jan. 7, 2009, the Justice Department sued the group and several members for alleged voter intimidation. After the Obama administration came into office two weeks later, the department asked that the case against three of the four defendants be dismissed.

The inspector general’s investigators reviewed more than 100,000 pages of documents and interviewed more than 135 people in scrutinizing the handling of that case.

The Washington Post reported in 2010 that the case had tapped into deep divisions within the Justice Department over how voting rights laws should be enforced.

“There were, in fact, significant differences in enforcement priorities over time, but we did not uncover evidence . . . sufficient to conclude that enforcement decisions were made . . . based on race or partisan considerations,” the report said. “We did, however, raise questions about the handling of some of those cases, including the New Black Panther Party matter, that we believe contributed to the appearance of politicization of the work of the Voting Section.”