She and Ocasio-Cortez both defeated older, white congressmen who were reliable liberal votes, but who didn't look like many voters in their districts.
Later during Pressley's victory party, her stepdaughter Cora stood in silence with tears rolling down her face as she listened to Pressley speak. She served as a senior aide to former Sen.
"Congratulations to my sister in service, [Ayanna Pressley], on continuing her historic path into Congress tonight", the socialist tweeted.
In his concession speech, Capuano said the district was clearly upset with the status quo and that he shared those feelings.
The House seat that Pressley is running for has no Republican challenger, which means that her win against Capuano sees her heading to Washington in November.
Pressley, who will likely win November's congressional race in heavily Democratic Boston, won almost 60 percent of the vote and would become the first black woman from MA elected to the House.
Ayanna Pressley didn't just upset Michael Capuano on Tuesday. Pressley defeated 10-term Rep. Michael Capuano, who had been endorsed by nearly every major figure in the state's political establishment, including Boston Mayor Martin J. Walsh, the New York Times reports. Pressley was endorsed by NY congressional candidate Alexandria Ocasio-Cortez and other progressives.
Amatul-Wadud, a mother of seven who touted her support for "Medicare for All" legislation, stumbled with an admission that, in 2012, she voted for Republican Scott P. Brown over Democrat Elizabeth Warren.
When given the chance to get behind the first black woman from MA headed to Capitol Hill, the Congressional Black Caucus chose to endorse Capuano instead. Her win comes at the tail end of a primary season in which black politicians have made a series of advances.
"The nature of the 44-year-old city councilor's [Pressley's] campaign - a woman of color taking on a white, male longtime congressman in a Democratic primary - drew immediate comparisons [to Ocasio-Cortez's campaign] Wednesday", he added.
However, two other Massachusetts Democrats, Reps.
They were contesting a primary to run for the seat held by U.S. Representative Niki Tsongas, who is retiring after 11 years.
With 13 percent of precincts reporting, Keating led businessman Bill Cimbrelo 86 percent to 14 percent when the AP called the race.