Santiago, a South End lawmaker, signals he may join Boston mayor’s race

State Rep. Jon Santiago, Democrat, at his home in the South End in 2018.Michael Swensen for The Boston Globe

State Representative Jon Santiago, a South End Democrat and emergency room doctor, has signaled he is preparing a run for mayor, including asking people whether they would back a potential campaign, according to three people who’ve spoken with him.

One person who spoke to Santiago told the Globe the lawmaker called him late last week, saying he intends to run and asked for his support. Another person said the 38-year-old hasn’t said he will launch a campaign, but that he is trying to gauge who he could include on a potential staff and finetune what his message would be.

“Those are the type of things that make it seem like he’s running,” said the person, who spoke on the condition of anonymity to describe their conversations. The person said he would back Santiago should he enter the race. “He’s not talking about should he run, but what are the things his candidacy would have.”

In a text message Thursday, Santiago indicated he has not made a decision. “Still seriously considering and having very encouraging conversations,” he wrote to a Globe reporter.

Politico first reported Thursday that Santiago had told people in calls he was getting into the mayoral race.

Should Santiago run, he would be the fourth candidate to join the field that includes three city councilors, all of whom are women of color: Andrea Campbell of Mattapan, Michelle Wu of Roslindale, and Annissa Essaibi George of Dorchester, who announced last week she was running.

Born in Puerto Rico, Santiago is in his second term in the Massachusetts House, representing parts of Roxbury and Back Bay. He first won the Ninth Suffolk seat in 2018 after unseating Byron Rushing, a 35-year incumbent, in their Democratic primary less than four years after he worked in Rushing’s office as an intern. A Yale University graduate, Santiago is an emergency room doctor at Boston Medical Center, and is a captain in the Army reserve.

Santiago told the Globe last month that he was considering a mayoral bid, and believes his experience as a representative, a doctor, and in the military lends itself to the role. “I think the opportunity to guide the city through this crisis would be an incredible opportunity,” he said then.

Mayor Martin J. Walsh, who is in the last year of his second term, was expected to run for re-election before news broke in early January that he was being tapped by President Biden to become the nation’s next labor secretary.

It set off a seismic effect on city politics, prompting an array of city leaders and elected officials to contemplate a mayoral run. City Council President Kim Janey, who will become acting mayor once Walsh steps down, is among those names, but she has yet to announce her plans.

The Boston City Council on Wednesday approved a home rule petition that would avoid a special election should Walsh leave to join the Biden administration before March 5.

Walsh would need to sign the petition , before it heads to the State House for approval from lawmakers and Governor Charlie Baker. Baker has indicated he would sign the petition should it reach his desk.

Danny McDonald of the Globe staff contributed to this report.