U.S. Sen. Bernie Sanders speaks Sunday at a “Fighting Back against Corporate Greed” rally on Cambridge Common. (Photo: Luciano Cesta)

U.S. Sen. Bernie Sanders headlined a labor rally Sunday on Cambridge Common, punctuating a slate of local and national leaders’ speeches that highlighted unionization and what they described as the greed of corporations.

The rally, “The Working Class: Fighting Back against Corporate Greed,” struck a combative tone and celebrated the recent growth of the labor movement in the United States. Well over 1,000 people attended, by police estimates – some among them saying that Sanders was as much a draw as showing support for the movement.

The Vermont independent is in his third Senate term, following 16 years in the U.S. House of Representatives, and said in April that he hasn’t ruled out a third presidential campaign if Joe Biden doesn’t run for reelection.

“We are seeing a rebirth of the American trade union movement from coast to coast,” Sanders told the crowd. “We are talking about blue-collar workers. We’re talking about white-collar workers. We’re talking about young people, we’re talking about older people.”

The International Brotherhood of Teamsters and the Association of Flight Attendants, part of a union originally known as the Communications Workers of America, also participated in the rally, and their presidents spoke.

A rally crowd listens to speakers Sunday on Cambridge Common. Police estimate that well over 1,000 people attended. (Photo: Luciano Cesta)

“At this park, there have been a lot of rallies, there have been a lot of rallies for social justice, voting rights, civil rights, LGBTQ+ rights, woman’s rights. And there is gonna be a hell of a lot more rallies right here,” said Sara Nelson, the president of the AFA-CWA. “But do you know what connects us all? And do you know what makes it possible for us to fight for our rights? Working people’s rights and that’s what we’re here to talk about today.”

Teamsters president Sean O’Brien highlighted how he thought business leaders such as Amazon’s Jeff Bezos, Tesla’s Elon Musk and Starbucks’ Howard Shultz helped the labor movement.

“There has never been a more inspiring time for organized labor and people to organize within their workplaces,” O’Brien said. “Because of those three nitwits and their bad behavior, they are actually helping us organize, they’re helping us mobilize. They are helping us strategize and they don’t know it.”

Union organizing and labor action has been becoming more visible in Greater Boston. Notably, several Starbucks stores recently unionized; one has been on strike for the past 36 days. Nurses recently went on a 10-month strike at St. Vincent’s Hospital in Worcester.

The Cambridge rally is part of a series of rallies Sanders has attended in support of the labor movement, with the most recent one being in Philadelphia on Saturday.