“Did you see him?!” Mr. Cummings roared, his voice rising in anger as he implored the congregation to confront the invisibility of young black men. “Did you see him? Did you see him?” The congregation roared back with applause.
In 2016, after a Justice Department investigation found that the Baltimore Police Department had routinely harassed members of minority groups, Mr. Cummings said the report “should infuriate us all.”
Mr. Cummings rose through the ranks of the Oversight Committee to become its top Democrat. In 2017 he ascended to the chairmanship, a role that gave him wide latitude.
He used his authority broadly, investigating everything from whether Wilbur Ross, the commerce secretary, was truthful in explaining why he had added a citizenship question to the 2020 census to policy matters, like military suicides and the high cost of prescription drugs. (Ms. Pelosi has appointed Representative Carolyn Maloney of New York as the acting chairwoman.)
The relationship between Mr. Trump and Mr. Cummings got off to a rocky start. In an April 2017 interview with The New York Times, Mr. Trump recounted their first meeting, “Elijah Cumming was in my office and he said, ‘You will go down as one of the great presidents in the history of our country.’”
The congressman promptly issued a statement saying he had been misquoted.
“During my meeting with the president and on several occasions since then, I have said repeatedly that he could be a great president if — if — he takes steps to truly represent all Americans rather than continuing on the divisive and harmful path he is currently on,” the statement said.
That year Mr. Cummings became ill, prompting his wife to abandon a bid for governor.
“He worked until his last breath,” she said in a statement on Thursday, “because he believed our democracy was the highest and best expression of our collective humanity and that our nation’s diversity was our promise, not our problem.”
Complete information on Mr. Cummings’s survivors was not immediately available.
Mr. Cummings was spiritual in his approach to his illness, and his life. In the interview in May, he told the story of how one day, when was in such dire pain that he thought he might faint, a hospital worker turned up at his bedside, saying the Lord had sent her to deliver a message: “I’m just trying to get your attention. I’m not done with you.”