The Ward 15 Democratic Committee last weekend backed Meetinghouse Hill activist Jennifer Johnson as its choice in the seven-way District 3 preliminary to replace outgoing Councillor Frank Baker.

Johnson, a member of the Ward 15 group, is also president of the Meetinghouse Hill civic group and a member of First Parish Church, Dorchester Arts Collaborative, and Bowdoin/Geneva Main Streets.

“For our members, Jennifer is the best known of the candidates for D3. Her leadership in many local organizations has proven her commitment to issues of importance to the people of Ward 15,” Ed Cook, Ward 15 co-chair, said in a statement. “She will bring that history and commitment to all the residents of District 3.”

Johnson received the two-thirds majority necessary on the first ballot.

The District 3 preliminary is set for Sept. 12. The group plans to interview the eight at-large candidates, who do not have a preliminary, in September.

The at-large field features three incumbents (Julia Mejia, Ruthzee Louijeune, and Erin Murphy) and five challengers (Henry Santana, Bridget Nee-Walsh, Clifton Braithwaite, Catherine Vitale, and Shawn Nelson). There are four at-large slots on the November ballot.

Louijeune, a Hyde Park resident who was first elected in 2021, said Monday that alongside her own reelection effort, she plans to vote and support Santana, a former Wu administration aide.

“Henry is a community leader and a dedicated public servant. I have witnessed his commitment to the people of Boston and his passion for creating positive change,” Louijeune said. “Henry’s campaign is centered around community, listening to residents, and prioritizing quality city services. With his experience, integrity, and dedication, I am confident that Henry Santana will be a strong partner on the City Council.”

Santana, a Columbia Point resident and an ex-aide to former District 8 Councillor Kenzie Bok, worked as Wu’s director of civic organizing until April.

He has also picked up support from District 4 Councillor Brian Worrell and his brother, Dorchester state Rep. Chris Worrell, among other Boston elected officials.