Rep. Elijah Cummings of Baltimore is dead at the age of 68.

Cummings died early Thursday at Johns Hopkins Hospital due to "complications concerning longstanding health challenges," per CBS News. In a statement, Maryland Democratic Party chairperson (and Cummings' wife) Maya Rockeymoore Cummings recalled the Democratic leader's decades-long work toward a stronger and more viable democracy for all.

"Congressman Cummings was an honorable man who proudly served his district and the nation with dignity, integrity, compassion, and humility," she said. "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. It's been an honor to walk by his side on this incredible journey. I loved him deeply and will miss him dearly."

Most recently, Cummings—chair of the House Oversight and Reform Committee—had been a crucial voice in the impeachment inquiry into Trump.

Cummings was a leader in multiple Trump-related investigations. Speaking at the National Press Club earlier this year, he urged "those in the highest levels of the government" to cease espousing a rhetoric "invoking fear, using racist language, and encouraging reprehensible behavior."

Kamala Harris, Chuck Schumer, and more shared Cummings tribute messages early Thursday: