The political wave and demands for change that have been battering the Democratic Party hit MA on Tuesday. In making his concession remarks, Capuano told his campaign team, "I will tell you Ayanna Pressley is going to be a good congresswoman and I will tell you that MA is going to be well served".
For example, she supports a House bill introduced by Rep. Betty McCollum (D-Minn.) that would mandate the US government cut its military assistance to Israel.
Keating, a former Norfolk County district attorney and state legislator, fended of a challenge from another democratic socialist, Bill Cimbrelo, in the 9th Congressional District, while U.S. Rep. Michael Capuano fell to Pressley in the 7th. Of Trump's impeachment, Pressley said: "I'd cast that vote, but a vote is not enough".
The victor of the primary in the majority-minority district - the only of its kind in MA - is expected to win in November because Republicans have not seriously challenged Democrats in the district for decades.
The race was just one of a slate of contested primaries in MA on Tuesday.
Voters head to the polls Tuesday in one of the last major primaries of the 2018 midterms, with several incumbent House Democrats in MA facing primary challengers for the first time in recent years. "Our president is a racist, misogynistic, truly empathy-bankrupt man", she told supporters. "It is time to show Washington, D.C., both my fellow Democrats, who I hope will stand with us and Republicans who may stand in our way. change is coming and the future belongs to all of us".
Trump has angered Democrats with his comments describing some immigrants as criminals, his verbal attacks on black athletes protesting racism and a vow to overturn the Roe v. Wade decision that legalized abortion across the United States.
Pressley's victory - as a younger woman of color - echoes the upset win, earlier this year in New York City, of political newcomer Alexandria Ocasio-Cortez, who also ousted a longtime congressional incumbent.
Although Pressley and her opponent shared a number of progressive values, her demand for the abolition of ICE, and her instance that she would bring a "bold activist leadership" to DC may have sealed her fate.
Pressley's victory is one in a growing line of stunning upsets by progressive candidates this primary season.
The seventh congressional district which she represents is the only district in her state to have a majority non-white population.
She will likely become the first African-American from MA elected to Congress this November, as there are no GOP lawmakers running in her district.
The Massachusetts 7th District race was also not a moderate-vs. -progressive match-up.
Indeed, Senator Bernie Sanders of Vermont remains a popular figure on college campuses and in some Democratic circles, and Senator Elizabeth Warren of MA shows every sign of preparing for a presidential campaign.
The ballot also features races for governor and a Republican contest for the U.S. Senate.
Pressley will vie for a seat in the House of Representatives after a career in Boston's City Council.
Pressley's victory over Capuano, a 66-year-old down-the-line liberal first elected to Congress in 1998, represents a generational, gender, and racial shift in Boston politics, and an upending of the wait-your-turn ethos that has pervaded the Democratic Party locally and statewide.
Pressley lives in the Dorchester neighbourhood of Boston with her husband, Conan Harris, and stepdaughter.