Rockymore Cummings told the Sun that she would resign from her party post before her election campaign. She is expected to launch her campaign in Baltimore on Tuesday.
Minutes after the release of the Sun interview, she announced her campaign on national television with Rachel Maddow of MSNBC.
"I want to expand and advance my husband's legacy while building and expanding my own legacy," said Rockeymoore Cummings in the Sun video.
She is a policy consultant and founder of the Washington DC-based policy firm Global Policy Solutions. She also ran for the Governor of Maryland last year before assuming the party presidency.
Following the death of Elijah Cummings, Maryland Governor Larry Hogan ordered a special election for the 7th district on 4 February. The general election is scheduled for April 28 on the same day as the state presidential election. Candidates must apply until 20 November.