Maryland Representative Elijah E. Cummings, a sharecropper’s son who rose to become the powerful chairman of a US House committee that investigated President Donald Trump, died early Thursday of complications from longstanding health issues, his office said. He was 68.

Cummings was a formidable orator who passionately advocated for the poor in his black-majority district, which encompasses a large portion of Baltimore as well as more well-to-do suburbs.

My warmest condolences to the family and many friends of Congressman Elijah Cummings. I got to see first hand the strength, passion and wisdom of this highly respected political leader. His work and voice on so many fronts will be very hard, if not impossible, to replace! — Donald J. Trump (@realDonaldTrump) October 17, 2019

As chairman of the House Oversight and Reform Committee, Cummings led multiple investigations of the president’s governmental dealings, including probes in 2019 relating to the president’s family members serving in the White House. Trump responded by criticizing the Democrat’s district as a “rodent-infested mess” where “no human being would want to live.” The comments came weeks after Trump drew bipartisan condemnation following his calls for Democratic congresswomen of color to get out of the US “right now,” and go back to their “broken and crime-infested countries.” Cummings replied that government officials must stop making “hateful, incendiary comments” that only serve to divide and distract the nation from its real problems, including mass shootings and white supremacy.

"He was an amazing man. He was not just a great congressman; he was a great man." --@SenSchumer on Rep. Cummings pic.twitter.com/z7YO7TsFKM — Morning Joe (@Morning_Joe) October 17, 2019

“Those in the highest levels of the government must stop invoking fear, using racist language and encouraging reprehensible behavior,” Cummings said in a speech at the National Press Club.

Cummings’ long career spanned decades in Maryland politics. He rose through the ranks of the Maryland House of Delegates before winning his congressional seat in a special election in 1996 to replace former Rep. Kweisi Mfume, who left the seat to lead the NAACP.

Cummings was an early supporter of Barack Obama’s presidential bid in 2008. By 2016, Cummings was the senior Democrat on the House Benghazi Committee, which he said was “nothing more than a taxpayer-funded effort to bring harm to Hillary Clinton’s campaign” for president.

Throughout his career, Cummings used his fiery voice to highlight the struggles and needs of inner-city residents. He was a firm believer in some much-debated approaches to help the poor and addicted, such as needle exchange programs as a way to reduce the spread of AIDS.

A key figure in the Trump impeachment inquiry , Cummings had been hoping to return to Congress after a medical procedure he said would only keep him away for a week. His statement then didn’t detail the procedure. He had previously been treated for heart and knee issues.

His constituents began mourning shortly after his death at 2:45 a.m. Thursday at Johns Hopkins Hospital.

In a statement, his widow, Maya Rockeymoore Cummings, chairwoman of Maryland’s Democratic Party, said “Congressman Cummings was an honorable man who proudly served his district and the nation with dignity, integrity, compassion and humility. He worked until his last breath 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.”

Cummings was born Jan. 18, 1951. In grade school, a counselor told Cummings he was too slow to learn and spoke poorly, and he would never fulfill his dream of becoming a lawyer.

“I was devastated,” Cummings told The Associated Press in 1996, shortly before he won his seat in Congress. “My whole life changed. I became very determined.” It steeled Cummings to prove that counselor wrong. He became not only a lawyer, but one of the most powerful orators in the statehouse, where he entered office in 1983. He rose to become the first black House speaker pro tem. He would begin his comments slowly, developing his theme and raising the emotional heat until it became like a sermon from the pulpit.

Cummings was quick to note the differences between Congress and the Maryland General Assembly, which has long been controlled by Democrats. “After coming from the state where, basically, you had a lot of people working together, it’s clear that the lines are drawn here,” Cummings said about a month after entering office in Washington in 1996.

Cummings chaired the Congressional Black Caucus from 2003 to 2004, employing a hard-charging, explore-every-option style to put the group in the national spotlight.

He cruised to big victories in the overwhelmingly Democratic district, which had given Maryland its first black congressman in 1970 when Parren Mitchell was elected.

The senior Democrat died from complications “of longtime health challenges”, his office said in a statement.