In a crowded, diverse mayoral field, where does Marty Walshâs base go? By Danny McDonald Globe Staff,Updated May 7, 2021, 5:33 p.m. Email to a Friend In 2017, Martin J. Walsh kicked off his reelection campaign outside Florian Hall in Dorchester.JohnTlumacki Martin J. Walshâs ascension from City Hall to US labor secretary not only triggered a crowded scramble in this yearâs mayorâs race but also raised the question of which candidate might inherit the voter base that powered the Dorchester Democratâs victories. While dozens of labor groups â Teamsters, painters, pipefitters â endorsed Walsh when he was running for mayor, providing his campaign with an army of volunteers, their support appears to be fracturing in this election.