Maya Rockeymoore Cummings resigned as chair of the Maryland Democratic Party on Monday night and announced she would seek the congressional seat vacated by the death of her husband, Rep. Elijah E. Cummings (D-Md.).

“I believe very strongly that I have the background, the focus, the commitment and the ability to take the reins and make a good run for this seat,” she told Rachel Maddow on MSNBC. She said her husband “wanted me to continue this fight.”

Rockeymoore Cummings, 48, joins a crowded field vying to represent a district where her last name is revered. Among her competitors is former congressman and NAACP chief Kweisi Mfume — a longtime friend of her husband’s and, like him, one of Baltimore’s favorite sons.

Mfume, 71, who represented Maryland’s 7th District in Congress before Elijah Cummings did, said last week that he was seeking the office again “to make sure that all he and others fought for is not lost, tossed to the side or forgotten.”

Rockeymoore Cummings, who did not return calls seeking comment Monday night, was relatively unknown in Maryland politics until she ran for governor in October 2017. She ended her campaign after three months, while her husband was hospitalized.

In December, Rockeymoore Cummings won a rare contested battle to lead the state Democratic Party, ousting Kathleen Matthews, who was backed by the party establishment. Rockeymoore Cummings said she wanted to lead the party after Democrats lost the 2018 gubernatorial election, with Gov. Larry Hogan becoming only the second Republican governor ever reelected in Maryland.

“We have a structural problem when it comes to the top of the ticket,” she said then. “And that structural problem will create a downward spiral for our party if we don’t fix it now.”

Much of her career was spent on Capitol Hill, first as chief of staff to congressman Charles B. Rangel (D-N.Y.). She worked as a senior resident scholar for health and income security at the National Urban League and as the vice president of research and programs at the Congressional Black Caucus Foundation. In 2005, she started Global Policy Solutions, a policy consulting firm.

A conservative watchdog organization in May filed a complaint with the Internal Revenue Service, alleging that there is insufficient separation between the consulting firm and a nonprofit organization that Rockeymoore Cummings started more recently. She dismissed the complaint as politically motivated.

As party chair, Rockeymoore Cummings focused on boosting Democrats in rural areas where Republicans are dominant, as well as in traditional Democratic strongholds. She ruffled some feathers by taking sides in a bitter fight over who should become speaker of Maryland’s majority-Democratic House of Delegates, and she has angered state Republican leaders by launching attacks on Hogan.

So far, six Democrats and three Republicans have filed to seek the 7th District seat, which includes parts of Baltimore City and Baltimore and Howard counties. In addition to Mfume, state Del. Talmadge Branch (D-Baltimore City), who serves as House majority whip, said he intends to run, and state Sen. Jill P. Carter (D-Baltimore City) has scheduled an announcement next week.

The filing deadline is Nov. 20, and the winner of the Feb. 4 Democratic primary will be heavily favored in the April 28 special election.

State Sen. Cory V. McCray (D-Baltimore City), vice chair of the state party, will take over as interim chair.

Rockeymoore Cummings told Maddow that she will undergo a double mastectomy on Friday, a prophylactic surgery based on her family history of breast cancer. She said she will recover over two to four weeks but will remain “laser- focused” on her campaign during that time.

“I’m going to get ahead of the curve and basically take the bull by the horns and stop it in its tracks before it ever begins,” she said of the surgery.

Jenna Portnoy contributed to this report.