Before stepping foot on Howard University’s campus, Skylar Wilson knew she would see more women there than men. But just how many more stunned her: Howard, one of the most elite historically Black colleges and universities in the nation, is only 25 percent men — 19 percent Black men.

“I was like, ‘Wow,’” said Ms. Wilson, a 20-year-old junior. “How is that possible?”

Howard is not unique. The number of Black men attending four-year colleges has plummeted across the board. And nowhere is this deficit more pronounced than at historically Black colleges and universities, or H.B.C.U.s. Black men account for 26 percent of the students at H.B.C.U.s, down from an already low 38 percent in 1976, according to the American Institute for Boys and Men. There are now about as many non-Black students attending H.B.C.U.s as there are Black men.

The decline has profound implications for economic mobility, family formation and wealth generation. Raj Chetty, a Harvard economist who uses large data sets to study economic opportunity, has found that the income gap between America’s Black and white populations is entirely driven by differences in men’s economic circumstances, not women’s.

The causes are many. Higher college costs, the immediate financial needs of Black families, high suspension rates in high school and a barrage of negative messages about academic potential all play roles in the decline of Black male enrollment and college completion. Howard estimates that its cost of attendance for undergraduates easily exceeds $50,000 a year.

“If we are serious about reducing race gaps in economic opportunity, household wealth, et cetera, then our attention should be squarely focused on economic outcomes for Black boys and men — period. Full stop,” said Richard Reeves, president of the American Institute for Boys and Men.

But now programs designed to nurture Black academic achievement may be dismantled by the Trump administration, which deems them “racist” diversity, equity and inclusion efforts. Cultural centers, mentorship programs, work force recruitment activities and scholarship programs are all threatened by the White House’s promise to cut funding to universities that do not eliminate what it calls racial preferences.

On Wednesday, Mr. Trump asked the Supreme Court to allow him to terminate more than $600 million in teacher training grants, which would decimate two of the Education Department’s largest professional development programs. Both were designed to place teachers in underserved schools and diversify the educational work force.

“It’s a perpetuating cycle,” said Dr. Cheryl Holcomb-McCoy, chief executive of the American Association of Colleges for Teacher Education. “If you don’t see other Black male educators, then it’s hard for you to see yourself in that position.”

On Thursday, the Department of Health and Human Services targeted California medical schools for maintaining what Trump administration officials called “discriminatory race-based admissions,” though bolstering the number of Black doctors has long been a goal of the medical establishment.

“Put simply, educational institutions may neither separate or segregate students based on race, nor distribute benefits or burdens based on race,” Craig Trainor, the Education Department’s acting assistant secretary for civil rights, wrote in a memo to universities in February.

Black educators say burdens are already distributed unfairly. Society undermines Black men’s belief in their own potential, starting from early education and continuing through professional development, said Dr. Derrick Brooms, executive director of the Black Men’s Research Institute at Morehouse College, an elite, all-male H.B.C.U. in Atlanta.

Colleges like Howard may be the starkest of manifestations. Payton Garcia, a Howard sophomore, recalled being one of three men in his introduction to philosophy class, which has about 30 students.

“We did a Cuba trip,” he recalled. “I was the only male that was in the class.”

Recent shifts in higher education, driven in part by conservative policies in Washington, have wrought large changes in predominantly Black colleges, positive and negative. The Supreme Court’s ban on race-based college admissions drove up interest in some H.B.C.U.s and strengthened the application pool overall, Dr. Brooms said. But he’s still concerned about the long-term trend.

Dr. Brooms said at this point, Morehouse may have to re-evaluate its recruitment strategy, including looking abroad: “Perhaps there may be some Black men in Canada who may want to attend.”

On campuses like Howard’s, the gender disparity is understood. Women run the place.

“Everybody knows that the women dominate this campus,” said Tamarus Darby Jr., a 20-year-old sophomore at Howard.

“You see predominantly women out here running for positions, and then you see their friends, young women, showing up for them and supporting them,” he said. “It’s different for the men.”

According to students and faculty at Howard, Black male students can have a difficult time finding both themselves and a community.

One night last October, young men gathered in small groups on the Howard yard and wrote down what they were most afraid of — “I have a fear of failure,” said Joshua Hughes, a senior who led the “burning of the fears” that night. “I have a fear of letting my family down. I have a fear of not living up to my full potential.”

Some read their fears aloud before tossing their writings into a giant firepit as a drum line banged African djembes.

In 2019, Calvin Hadley, then a senior adviser to Howard’s president, was asked how Howard could better engage men on campus. He put together a survey of students, faculty and staff, and then hosted several barbershop listening sessions. Something clicked.

“We had these very detailed, emotional conversations around manhood, around masculinity, around relationships,” said Mr. Hadley, now Howard’s assistant provost for academic partnerships and student engagement.

Male fears can work against college attendance, students said. Fears of failure may deter Black men from higher education, even as fears of letting their families down drive them prematurely into the work force, before their earning potential can be reached.

Mr. Darby said many of his friends didn’t have parents or family who attended college, or they thought the costs were prohibitive. “So they were trying to find those other avenues to make money and to be successful, not thinking that college was the number one thing that was going to get you there,” he said.

As a middle schooler, Jerrain Holmes, a 20-year-old sophomore, recalled thinking: “College? What is college?” He added, “I knew I just wanted a job.”

But in his Detroit-area high school, he enrolled in a college readiness program, and it made all the difference.

“As a general proposition, young men are arriving on college campuses less skilled academically than women,” Mr. Reeves said. “That’s even more true of men of color, Black men.”

That leads to problems of completion, which are at least as significant as declining enrollment.

The first year of college is crucial for male retention, and a lack of services can lead young men to feel isolated or that they don’t belong, Dr. Brooms said.

“If you can show you can keep people, that folks can persist to graduation, that becomes a recruitment tool itself,” said Dr. Brooms.

On a recent warm, breezy spring day on campus, Howard students lay on blankets, chatting. Some set up tables to sell merchandise, displaying the famed entrepreneurial “Howard hustle.” Others campaigned for student senate or royal court. The gender disparity was on the minds of the students.

Christian Bernard, a 22-year-old senior from affluent Potomac, Md., is a third-generation legacy student. He was on the yard selling items from his clothing brand, emblazoned with the slogan “Worth It.” He started the brand amid the turmoil and grief of June 2020, after the murder of George Floyd by a Minneapolis police officer and the swell of Black Lives Matter demonstrations.

He chose Howard for its soccer program and his family ties. Before injuries derailed his athletic career, he made strong friendships with his teammates.

“There’s a lot of male camaraderie here at Howard,” he said.

Those studying the challenges that young Black men face are careful to avoid a battle of the sexes. Women have faced historical challenges of their own. Some people perceive female gains as a threat to men in a zero-sum battle for resources and power.

Mr. Reeves said that is a mistake, particularly when it comes to family formation.

Asking the young men on campus how the gender gap affects dating will draw a sheepish grin. They understand their advantage.

Young women are thinking about it too. “Those ratios,” said Nevaeh Fincher, a sophomore, can be “rough.”

“A lot of the boys feel like they’ve got options,” Ms. Fincher said, “which, if we’re being honest, they do.”

The lack of college-educated Black men could change family structures and bread winning patterns, placing more financial burdens on Black women. College-educated Black women already have higher lifetime earnings than college-educated white women because they work more years over the course of their lives, despite lower annual earnings, according to the Kansas City Federal Reserve.

For young women who care about the future of Black America, in general, all of this is alarming.

“We see a lot of school programs and districts that are giving up on students and giving up on Black men before they even give them a chance,” said Ms. Wilson. She’s seen it in the male students she mentors, who say their teachers don’t offer much encouragement.

“They expect them to be bad,” she said. “They expect them to be problems.”