Pressley has drawn comparisons to Alexandria Ocasio-Cortez.
Another 10-term incumbent went down to defeat in a Democratic primary Tuesday night.
Boston City Councilwoman Ayanna Pressley won the Democratic primary Tuesday in Massachusetts' 7th Congressional District, ousting longtime Democratic Rep. Michael Capuano from the deep-blue, Boston-based district.
Another difference is that while New York Rep. Joe Crowley didn't take Ocasio-Cortez's candidacy seriously and skipped debates with her, Capuano recognized the threat from Pressley from the start.
Ayanna Pressley, now serving on the Boston City Council, beat the 10-term Democrat in another big Democratic upset.
Pressley argued that while Capuano was a consistent progressive vote in Congress, she would provide "activist leadership". Pressley was endorsed by Ocasio-Cortez, and has been profiled in several news outlets. "Ours was truly a people powered, grassroots campaign. that dared to do what Massachusetts Democrats aren't supposed to do". However, Pressley had the endorsement of popular state Attorney General Maura Healey.
Capuano was conceding shortly after 9 p.m. after it was clear he didn't have the votes to keep the seat he's held for two decades.
"Voters might be hesitant to move on from Capuano after his years of experience and the seniority he has accumulated in Congress", the Boston Globe editorial board wrote.
There is no Republican on the ballot in this Democratic bastion - an urban district that encompasses Boston, Cambridge and surrounding suburbs, much of the area once represented by a young John F. Kennedy, and now often called the "Kennedy seat".
Pressley said that Ocasio-Cortez's victory in June was a boost for her campaign, getting some skeptics off the fence and further emboldening those who were already supporting her. "It's not just good enough to see the Democrats back in power but it matters who those Democrats are". Unlike Ocasio-Cortez, who was running against a more moderate Democrat in Crowley, Capuano is a member of the Congressional Progressive Caucus with a solidly left-leaning legislative record.
Pressley thought was also helped by some cracks in establishment support for Capuano. "Ayanna Pressley is going to be a good congresswoman and MA will be well served".
Pressley is a heavy favorite in November in one of the most Democratic districts in the country.