Since Mr. Riley’s resignation, students have staged a sit-in at the president’s office, marched on campus and passed a resolution in the Student Senate “reaffirming” the university’s commitment to “protecting the freedom of speech and academic freedom.” The outrage ignited over Mr. Riley’s departure — and the university’s silence in explaining why — has become a galvanizing moment for black students, with many of them now mobilized and ready to more directly tackle the university’s past.

At a recent Student Senate meeting, which tend to draw meager crowds, dozens of people crowded into a cafeteria to discuss the resolution. A freshman told of men in a passing vehicle who had hurled slurs at her and fired paintballs. A senior argued that the Senate, composed mostly of white students, did not grasp the extent of its privilege — “you can’t even fathom how much you gain and how much we lose,” the woman said.

“Are you here for us?” Udonna Simpson, a senior political science major, asked in a passionate address before the resolution was passed without any dissent. “I ask you to show us you’re here for us, to show us you care about us, to show us you are not racist.”

Outside of a terse statement confirming Mr. Riley’s resignation, neither the university nor Mr. Riley has commented further. University officials, through a spokeswoman, declined to say anything more, and Mr. Riley did not respond to multiple requests for an interview.

The silence reflects the frustration faculty members said they feel over the pace of improving diversity, an issue with which they wrestled long before Mr. Riley’s resignation, said Pamela Payne Foster, a professor of community medicine and population health.

“I do believe we’re at a critical point,” she said, “where the question is being asked: At what point are we going to tip this over, or is it going to stay where it is? The fight is a pretty formidable fight.”