Boston City Councilwoman Ayanna Pressley is poised to become Massachusetts’ first female African-American in Congress. In an upset over the incumbent, 10-term Congressman Rep. Mike Capuano, Pressley won 59-41, scoring a 17,500 vote victory.

She has no Republican challenger in the solid Democratic district, so she will be headed to Congress in the fall.

The win was particularly shocking because Capuano, who is white, not only won endorsements from major unions but also from Congressional Black Caucus. Supporters included famous civil rights activist Rep. John Lewis of Georgia, former Massachusetts Governor Deval Patrick, and long-time liberal figure Rep. Maxine Waters of California.

Despite support from such prominent African-Americans, Pressley won the day by delivering a fervent social change agenda, including abolishing the Immigration and Customs Enforcement Agency. Capuano may have also hurt himself when he criticized the kneeling national anthem protest by Colin Kaepernick as being “not productive.”

Pressley’s support was driven by powerful emotional messaging. She is a sexual assault survivor, raised in a single-mother home, and her motto was direct: “The people closest to the pain should be closest to the power.”

Pressley joins democratic socialist Alexandria Ocasio-Cortez in both staging a shocking upset, and with an “equity agenda” that skewed to the left of the incumbent. Her website says that she wants to “Restructure federal programs to reimburse school nurses for covered health care service…ensure access to school-based mental health services…advocate for lead poisoning prevention and childhood asthma prevention”

She is also an advocate of Medicare-for-all, and in regard to gun control, says, “Massachusetts has some of the strongest gun laws in the nation, but guns continue to flood our communities, many acquired in surrounding states with looser laws – that’s why comprehensive gun control at the national level is so important. I support federal legislation that would ban assault weapons, bump stocks, and high-capacity magazines, raise the legal age to purchase a gun to 21, and require comprehensive background checks for all gun sales.”

Her other positions include “ensuring the right to counsel for unaccompanied minors…ending the cash bail system…prioritizing treatment, not prison, for people with mental health or substance abuse issues…legalizing marijuana…[and] addressing income inequality by [taking] immediate steps to raise the Federal minimum wage to at least $15 an hour and expand the Earned Income Tax Credit so that lower income families keep more of their hard-earned money. And we need to pass paid family leave legislation, so that parents and caregivers don’t lose vital income when they need to take care of a sick child or aging parent.

However, two other Democrats that leaned farther left lost their primaries against other incumbents. Rep. Richard Neal beat Tahirah Amatul-Wadud, another African-American woman, while Rep. Stephen Lynch defeated Brianna Wu, a developer of video games.

Meanwhile, Republican Governor Charlie Baker won his primary 64-36, and will face off against Democrat Jay Gonzalez, who won by roughly the same margin. Republican state legislator Geoff Diehl will face off against U.S. Senate incumbent Democrat Elizabeth Warren, currently a prohibitive favored to win re-election.

Massachusetts’ 3rd District remains a toss-up as far as the Democratic primary winner. Lori Trahan had a 52 vote lead over Daniel Koh, according to the NY Times results as of this writing. Neither candidate has conceded yet. The winner will oppose Republican Rick Green.