Rep. Elijah Cummings, D.-Md., was one of the most powerful Democrats in Washington as the chair of the House Government Oversight committee that is overseeing numerous investigations into the Trump presidency. But his political career began long before the current administration, and before now, his impact was often felt most by the residents of places like his native Baltimore and other major cities across the country. 

Cummings died Thursday of complications from long-standing health problems. He was 68.

He was an advocate in Washington for the poor in his majority black district, which included a large portion of Baltimore and more well-to-do suburbs. But before he became a staple on Capitol Hill, the Baltimore native built his career in a place that is often on the receiving end of some of the worst characterizations about city life.

Cummings made it his responsibility to elevate the concerns of the residents of America's urban areas on Capitol Hill.

When President Donald Trump blamed Cummings in July for Baltimore's challenges, characterizing the congressman's district as "a disgusting, rat and rodent infested mess," Cummings immediately invoked the people who live in the city.

"Mr. President, I go home to my district daily. Each morning, I wake up, and I go and fight for my neighbors," he tweeted. "It is my constitutional duty to conduct oversight of the Executive Branch. But, it is my moral duty to fight for my constituents."

And those who knew him professionally affirmed that idea.

Sherrilyn Iffil, president and director-counsel of the NAACP Legal Defense and Educational Fund, Inc., a legal organization pursuing racial justice, said Cummings' work on urban issues was at the foundation of his career.

"He was fiercely committed to Baltimore City, but committed most of all to fighting for justice and opportunity for those living at the margins," she said in a statement. "LDF has been privileged to work with Rep. Cummings for nearly a decade on housing discrimination, transportation and policing reform issues in Baltimore City. His focus was always on measures that would lift people up."

Cummings often appealed to morals and values to change policy. In announcing the impeachment hearings last month, he invoked concerns about legacy in an attempt to encourage lawmakers to make the most ethical decisions.

"When the history books are written about this tumultuous era, I want them to show that I was among those in the House of Representatives who stood up to lawlessness and tyranny," he wrote. "If Senate Republicans choose to close their eyes, put party over country, and forego their duty under the Constitution, the history books will show that too."

But he also believed in the power of data to improve the lives of those throughout the country's cities, said Nancy La Vigne, vice president for justice policy at the Urban Institute, a D.C.-based think tank focused on economic and social policy research.

"I knew Rep. Cummings best through his and his staff's keen appetite for research and evidence to guide the policies that he developed and promoted," she told the Washington Post. "As a representative of Baltimore, he was in a unique position to have a national platform for a conversation about how we need to address bias in policing and the detrimental impact it has on people of color. A lot of my research is in the context of people leaving prisons and returning to their communities, and he was a fierce advocate of giving people second chances."

Earlier this year, Cummings introduced the Promoting Reentry through Education in Prisons Act to make it easier for former inmates to pursue the educational opportunities they need to gain employment after being released from prison.

"Education gives us direction and often provides people with the tools they need to leave the path that originally led them to incarceration," he said in May. "Educational programs are proven to reduce recidivism, and it is imperative that every incarcerated individual is provided with the opportunity to better themselves and leave prison ready to fully contribute to their communities."

Rep. Karen Bass, D.-Calif., the chair of the Congressional Black Caucus, said keeping issues that most affect urban residents was at the core of who Cummings was.

"Rep. Cummings was Baltimore and Baltimore was in his heart and soul," Bass said. "And yet at the same time, he knew that the challenges faced by the people in Baltimore are faced by many cities around the country. So his elevating issues such as police-community relations and health-related issues, like prescription drugs, disproportionately impacted poor communities.

"His loss is a loss for our country."

Eugene Scott is a reporter covering identity politics for The Fix, a Washington Post product.