Mr. Mfume won the seat in a contest conducted predominantly by mail, with only three polling sites open because of safety concerns during the coronavirus pandemic. A former Baltimore city councilman, he was first elected in 1986 to represent Maryland’s heavily Democratic Seventh Congressional District, where he served until 1996, when he left to join the African-American civil rights group; Mr. Cummings won election to succeed him.
After winning a crowded Democratic primary, which included Maya Rockeymoore Cummings, the widow of the former representative, Mr. Mfume, 71, defeated Kimberly Klacik, a Republican strategist and member of the Baltimore County Republican Central Committee.
Ms. Klacik drew national attention in July after she assailed Mr. Cummings and showed footage of boarded-up houses and trash-strewn areas of Baltimore on “Fox & Friends,” prompting President Trump to label Mr. Cummings, then the chairman of the powerful House Oversight and Reform Committee, “a brutal bully” who represented a district that had become a “disgusting, rat and rodent infested mess.”
The founder of a nonprofit that helped disadvantaged women enter the work force, Ms. Klacik campaigned as an ardent supporter of Mr. Trump, vowing to improve oversight over taxpayer spending and pursue a conservative agenda.
In the district, which includes parts of Baltimore and Howard Counties in Maryland, Democrats outnumber Republicans by a margin of 4 to 1 and had returned Mr. Cummings to Congress 13 times. His death in October, after months of poor health, was a devastating loss for House Democrats, who in the words of Speaker Nancy Pelosi, viewed him as “our North Star.”
Though Representative Carolyn B. Maloney, Democrat of New York, has succeeded Mr. Cummings to lead the oversight committee, Mr. Mfume will complete the remainder of Mr. Cummings’s term. His name will appear on the state’s primary ballot in June, when he will again seek the party’s nomination to compete in the general election for a full term beginning in January.
Mr. Mfume centered his campaign on his decades of experience in Baltimore as a city councilman, congressman and civil rights leader.
“At this critical time for our country, and every neighborhood in every corner of Maryland, we need a full and active delegation fighting side by side to protect the health, rights and dignity of every person in our state,” said Senator Ben Cardin, Democrat of Maryland, who was first elected to the House with Mr. Mfume.
“As both the predecessor and now successor to our friend and colleague Elijah Cummings, I know Congressman Mfume will serve the people of the Seventh Congressional District in a way that honors Elijah’s deep legacy and builds on his incredible record,” he added.
Mr. Mfume abruptly left his post as head of the N.A.A.C.P. in 2004, and at the time was credited with helping the organization, the nation’s oldest civil rights organization, recover from a quagmire of debt.
But a review of records conducted by The Baltimore Sun found that his departure came after an employee threatened to sue the organization and Mr. Mfume for sexual harassment, as well as concerns about Mr. Mfume’s management. The executive committee of the organization’s board ultimately voted not to renew his contract.
Mr. Mfume, in a statement to The Sun, said that “sometimes strong-willed leaders have differences of opinion.”