Community activist John Barros kicked off his mayoral bid on Thursday, officially entering the already crowded field.

The Dorchester resident has served on the School Committee and as head of the Dudley Street Neighborhood Initiative. He resigned from the School Committee earlier this week.

“I will ensure a strong local economy, supporting small businesses, leveraging downtown and unleashing the potential of entrepreneurship and innovation throughout the city,” he told a crowd of about 50 supporters at the Haley House Café in Roxbury.

The crowd included folks like Isaura Mendes, an anti-violence activist and Judith Kurland, a former chief-of-staff to Mayor Thomas Menino. The longtime mayor has said he is not running for another term.

Kurland, who is now at UMass Boston’s Center for Community Democracy and Democratic Literacy, said Barros displays “optimism about people and neighborhoods.”

“He’s one of the greatest community organizers I’ve ever seen,” she said.

Barros has hired Matt Patton, who has worked on campaigns for Gov. Deval Patrick and U.S. Sen. Elizabeth Warren, as his campaign manager.

Additional Boston political developments below:

-- Former state Rep. Charlotte Golar Richie applied for nomination papers to run for mayor on Friday, the Globe’s Andrew Ryan tweeted. Sources told the Reporter earlier this week that Richie met with supporters on Sunday to tell them that she is running.

-- State Rep. Marty Walsh and District 5 Councillor Rob Consalvo also applied for mayoral nomination papers yesterday. Walsh plans to have his formal kick-off on Saturday, May 4 at the Strand Theater, his campaign said yesterday. Consalvo’s kick-off is set for Thursday, May 16 at the Cedars of Lebanon in Jamaica Plain.

-- Former City Councillor At-Large Michael Flaherty is leaning at running for at-large this year, he said yesterday, in a brief interview at Broadway MBTA Station. Flaherty, a South Boston native, also said he is staying neutral in the First Suffolk Senate race, which has a three-way Democratic primary scheduled for April 30. Flaherty unsuccessfully ran for mayor in 2009 and campaigned to get his old seat back in 2011.

-- After writing a post titled, “I Think I May Have to Withdraw from the Mayor's Race Before I Even Begin” and receiving flak from his fans, Barstool Sports’ David Portnoy says he’s definitely running for mayor. “If you guys want me to run for mayor, I’ll run for mayor,” the Dorchester resident said in a YouTube video posted on his site yesterday. “You’re going to have to donate, you’re going to have to buy the ‘El Prez for El Mayor’ shirts, I’ll go get this lawyer I have to put a retainer on… You better register to vote, you better do the signature and I’m going all out.”

-- Yesterday, Jack Kelly, a former City Hall aide from Charlestown applied for nomination papers for at-large. Blog post from January is available here.