WASHINGTON — At a training last month for hundreds of fair-housing advocates, Housing and Urban Development Secretary Ben Carson crowed about his suspension of an Obama-era rule mandating that communities fix long-standing patterns of segregation.

The regulation, hailed as one of the most ambitious efforts to fight racial bias in housing in decades, was too burdensome on cities, he said, according to four people present. So was another Obama rule that held lenders and landlords liable for policies that led to discrimination even if none was intended, he added.

The audience, many of whom had spent years working to make sure marginalized groups get equal access to housing, was stunned. “Tone deaf,” said one attendee.

The scene illustrated the uncomfortable reality for Carson as he nears the end of his second year as HUD secretary. Though he is charged under the law with eliminating discriminatory housing practices, Carson is also a longtime skeptic of using government power to remedy such inequality.

Beyond his attempts to roll back the agency’s fair-housing rules, Carson is overseeing a department whose fair-housing budget and staffing have been cut. And, notably, he has departed from the practices of recent Democratic and Republican predecessors of using their secretarial power to root out systemic racial discrimination by launching broad-based investigations into bias by banks, real estate companies and others.

Carson has only once used his authority as HUD secretary to scrutinize widespread housing discrimination, moving ahead under public pressure on an investigation against Facebook that was initiated during the Obama administration.

President Barack Obama’s HUD secretaries used the tool — known as “secretary-initiated complaints” — an average of 10 times per year, while President George W. Bush’s second HUD secretary used it an average of five times per year, according to a Washington Post examination of the agency’s annual fair-housing reports to Congress.

“If you’re going to have this position, you have to use it,” said Kim Kendrick, who began championing the use of secretary-initiated actions as the HUD assistant secretary for Fair Housing and Equal Opportunity during Bush’s second term. “You can potentially have an impact nationwide.”

The Obama and Bush administrations wielded the HUD secretary’s enforcement powers to investigate home insurance companies that refused to sell policies in African-American neighborhoods, real estate brokers who refused to show certain houses to black home buyers, and mortgage lenders that illegally denied loans to black and Hispanic borrowers or charged them higher rates, according to HUD records.

The intense scrutiny of racist or otherwise discriminatory housing practices resulted in financial compensation for large numbers of victims and forced offending companies to change practices, according to HUD’s reports to Congress.

Defenders of Carson, who as a presidential candidate decried a federal effort to desegregate American neighborhoods as “failed socialist experiments,” argue he is not retreating from the agency’s civil rights mission. Rather, HUD spokesman Jereon Brown said, the agency is prioritizing a backlog of 600 individual complaints of discrimination instead of initiating broad-based actions.

More than half of the individual complaints pertained to discrimination on the basis of disability, according to HUD. A quarter pertained to race, and fewer than a third to national origin.

“Nearly 500 people had their cases resolved” since 2017, Brown said, “versus focusing our resources on larger secretary-initiated cases.”

Each year, HUD receives thousands of complaints from individuals alleging discrimination that the agency is required to investigate. Unlike broader secretary-initiated cases that seek redress for victims who may not even have been aware that their rights had been violated, individual complaints may focus on issues such as wheelchair access at an apartment building, sexual harassment by a landlord or allowances for service animals, former and current HUD officials say.

Carson’s focus on responding to individual allegations of bias over pro-actively seeking solutions to patterns of disparity aligns with Republican orthodoxy, said Robert Driscoll, a deputy assistant attorney general in the Justice Department’s civil rights division during the Bush administration.

“If an individual is rejected for housing because he is black — those kinds of cases should always gain traction in a conservative administration,” Driscoll said. “Republicans are more likely to see problems with defining discrimination based on group statistics.”

Other civil rights attorneys say that while it’s important to resolve individual complaints of discrimination, those efforts are unlikely to address structural inequality or result in widespread change.

“The fact there has only been one complaint by Secretary Carson says to everyone that HUD will no longer be in the business of aggressively enforcing fair-housing laws,” said Aderson Francois, a professor at Georgetown University Law Center who directs the Institute for Public Representation Civil Rights Law Clinic. “HUD is in danger of becoming something of a zombie agency.”

After initially suspending a preliminary investigation into Facebook that began under Obama in late 2016, Carson in August filed his sole secretary-initiated complaint against the platform.

He accused Facebook of giving landlords and developers advertising tools that made it easy to exclude groups protected by the Fair Housing Act. Among the many ways Facebook did so, HUD said: literally drawing a red line around majority-minority ZIP codes and not showing housing ads to users who live in those areas.

Facebook said its policies prohibit discrimination and that it would continue working with HUD to address the agency’s concerns.

Brown, the HUD spokesman, said Carson chose to exercise his authority against Facebook because the case “potentially affects millions.”