Ben Carson and Donald Trump at Trump Tower in August. (Carlo Allegri/Reuters)

Donald Trump’s selection Monday of retired neurosurgeon Ben Carson to head the Department of Housing and Urban Development sets up what could be a collision between the nominee’s philosophical aversion to social safety-net programs and an agency that administers some of the government’s most expansive programs for helping minorities and low-income people.

If Carson remains true to his political commentary about the nation’s housing programs, he could pursue a conservative agenda sharply at odds with efforts by the Obama administration to promote racial integration in housing and with other anti-segregation policies championed by minority groups such as the NAACP. Carson might also abandon or place new restrictions on government subsidies and other programs that conservatives criticize as fostering a culture of overreliance on government handouts, according to housing advocates alarmed by his nomination.

It could prove difficult, however, for Carson to manage, much less change the fundamental course of an organization as massive as HUD. By his admission, Carson has never run an organization of that size and is far from fluent in housing-policy issues. His leadership of the department will be a test case for Trump’s stated governing philosophy that it is better for Washington outsiders, even those with no policy experience, to hold the levers of federal power.

“Ben Carson has a brilliant mind and is passionate about strengthening communities and families within those communities,” Trump said in a statement announcing his decision to nominate Carson.“We have talked at length about my urban renewal agenda and our message of economic revival, very much including our inner cities. Ben shares my optimism about the future of our country and is part of ensuring that this is a Presidency representing all Americans.”

President-elect Donald Trump named Ben Carson as his nominee for housing and urban development secretary. Here's what you need to know about the former GOP presidential candidate. (Sarah Parnass,Osman Malik/The Washington Post)

Carson is receiving counsel from Alphonso Jackson, HUD secretary under President George W. Bush, who has suggested he rely heavily on the department’s professional staff to help him set priorities when he takes over the agency. “We have discussed that over the last couple of weeks,” Jackson said in an interview. “The Senior Executive Service people at HUD are extremely intelligent and valuable to any secretary, if he will listen to them.”

Major changes to the government’s role in housing would require Congress to act, but policy experts said Carson will have the power to make many changes on his own using his department’s rulemaking authority.

He could, for instance, seek to change rules that determine who is eligible for housing assistance and institute tougher work requirements for people in subsidized housing.

Advocates said they are concerned about Carson’s comments that safety-net programs foster dependence in low-income people.

“Coming to lead an agency that serves the poorest people in the country with a philosophy of if people are that poor it’s because they’re not trying hard enough could have a big impact on the people HUD serves,” said Diane Yentel, president of the National Low Income Housing Coalition.

HUD, with a $49 billion budget and about 8,300 employees, has its origins in President Lyndon B. Johnson’s “Great Society.” Its mission includes enforcing anti-discrimination laws, assisting low-income applicants in obtaining home mortgages and operating more than 3,000 local public-housing authorities.

The agency is likely to attract attention in Trump’s administration, given the president-elect’s frequent and often criticized descriptions of hellishly violent urban communities on the campaign trail.

“You have so many things, so many problems, so many horrible, horrible problems,” Trump said at a rally before the election. “The violence. The death. The lack of education. No jobs. We’re going to work with the African American community, and we’re going to solve the problem of the inner city.”

Carson has spoken about the desperation he sees in urban areas as well but uses a more modest tone than Trump.

“We have much work to do in strengthening every aspect of our nation and ensuring that both our physical infrastructure and our spiritual infrastructure is solid,” Carson wrote in a Facebook post last month.

Congress will have a significant budgetary role in determining what pieces of Carson’s agenda take effect. Housing experts said they expect to see a decline of HUD’s already-shrinking budget, assuming that Trump follows through on his pledge to pay for increased spending on the military with cuts to domestic programs, which could narrow Carson’s range of options.

The nominee’s history gives him a pronounced, often controversial view on the roots of urban poverty.

Born into a struggling family on the southwest side of Detroit, Carson was educated at Yale University and the University of Michigan before he began a celebrated surgical career at Johns Hopkins University in Baltimore. He credits his achievements to his Christian faith and the high expectations of his mother, an illiterate domestic servant who sought never to take government assistance, though she sometimes did.

“She worked very hard, leaving very early in the morning, getting back very late at night,” he said in interview last year with The Washington Post. “Sometimes we didn’t see her for a week. She didn’t like the idea of dependency. Even if she sometimes took government aid, she always wanted to be independent. She would get in arguments with others who would say, ‘There’s aid for dependent children — you don’t need to be working.’ ”

The biggest shifts under Carson could come in the area of fair housing, experts said. The Obama administration is just starting to implement a new rule requiring local communities to study and report on patterns of racial and income disparity in housing, with HUD overseeing the strategy. The federal government is giving these communities detailed data on poverty rates, school demographics, where minority groups live and whether they are segregated from white neighborhoods. Where segregation exists, HUD and local officials are supposed to come up with plans to reduce it.

Conservative critics have called the policy government overreach, and Carson wrote last year that requiring cities and towns to publicly report racial disparities in housing would “fundamentally change” communities by requiring affordable housing to be built in wealthier neighborhoods.

In a Washington Times op-ed, he issued a strong warning against the policy, comparing it to “mandated social-engineering schemes” typical of socialism.

“These government-engineered attempts to legislate racial equality create consequences that often make matters worse,” Carson wrote. “There are reasonable ways to use housing policy to enhance the opportunities available to lower-income citizens, but based on the history of failed socialist experiments in this country, entrusting the government to get it right can prove downright dangerous.”

As housing secretary, Carson could urge Congress to take this authority away from HUD, experts said. But even if that didn’t happen, Carson could direct his staff not to enforce the rules, by moving resources out of the fair-housing division and into other areas of the department.

“Just sort of ignoring it on its own could mean much less oversight,” Yentel said.

Carson could seek guidance from House Speaker Paul D. Ryan (R-Wis.), who has proposed overhauling federal housing policy using the changes to welfare in the 1990s as a model. That could mean imposing a work requirement for federal housing aid and limiting the amount of time beneficiaries may use public housing.

Housing experts said they also anticipate a shift away from enforcing fair-housing laws and responding to complaints of discrimination and toward creating more of a role for the private market in housing programs. Trump’s transition team for HUD has several members from the world of housing finance, which could help the agency provide government-subsidized mortgages for low-income home buyers.

Robert Silverman, a housing expert at the University of Buffalo, predicted that Carson will reduce the level of scrutiny these lenders face about how loans are distributed to minority groups. “Less regulation will allow them to originate loans they might consider higher-risk,” Silverman said.

He also expects to see a larger role for private developers in revitalizing existing public housing apartments or building new ones, a strategy the Obama administration has used to some degree. Developers benefit from tax credits when they take on federal projects such as these, but experts say they will have less incentive to do so if Trump reduces many of their corporate taxes.

Groups representing the government’s more than 3,000 local public-housing authorities said Carson’s expected push for a weaker government hand in housing could also bring some relief — from regulations they say are too time-consuming and expensive to carry out. Thousands of civil servants at HUD are eligible to retire, and from 2005 to 2014, the agency has lost the greatest percentage of full-time employees who have not been replaced of any federal department, according to the Government Accountability Office.

In recent years, there have been new requirements to employ public-housing residents in redevelopment projects, the fair-housing rule and now a no-smoking rule.

“We’re concerned that HUD can’t fulfill many of its mandates,” said Tim Kaiser, executive director of the Public Housing Authorities Directors Association.

These are complex issues that bedevil policy experts, but Jackson said Carson’s leadership abilities will see him through the challenges of running HUD.

“Ben is a leader, and he engenders energy in people,” he said. “I don’t want to prejudge him.”