Announcing democratic consensus of its members across all three regional chapters nationwide, the United Electrical, Radio and Machine Workers of America said it was officially endorsing Bernie Sanders for president on Sunday.

The 35,000-member UE—which uses "the members run this union" as its tagline—said it was support from rank-and-file members which drove the endorsement.

"As more of our members around the country have seen and heard Bernie over the past few months, they’ve seen that his policies and priorities match our own," said the UE's general president Peter Knowlton in a statement. "There has been a groundswell of support for Bernie with members volunteering for the campaign."

Knowlton described Sanders as "the most pro-worker, pro-union presidential candidate I have seen in my lifetime" and called the chance to put someone like him in the White House "a unique opportunity that workers and unions must not pass up."

According to the Sanders campaign, more than 100 national and local unions, representing over 1.5 million workers, have endorsed his candidacy so far.

While campaigning in Rhode Island on Sunday ahead of key primary contests there and other northeastern states on Tuesday, Sanders welcomed the latest endorsement from organized labor.

"I thank the 35,000 members of the United Electrical Workers for their endorsement," Sanders said. "During my 25 years in Congress, I have been proud to stand side by side with the UE fighting to increase the minimum wage to a living wage; to guarantee health care to every man, woman and child as a right; to make it easier for workers to join unions; to rebuild our crumbling infrastructure; to transform our nation’s energy system; and against disastrous trade agreements like the North American Free Trade Agreement and normalized trade with China which have destroyed millions of decent-paying jobs in America."

Though rival Hillary Clinton has also garnered numerous endorsements from major labor unions throughout the campaign season, The Intercept's Ziad Jilani pointed out earlier this year how one of the key differences in the manner of such endorsements has been that Sanders tends to get group endorsements "when members decide" and Clinton generally receives them "when leaders decide." As Jilani noted in his January article, "Every major union or progressive organization that let its members have a vote endorsed Bernie Sanders... Meanwhile, all of Hillary Clinton’s major group endorsements come from organizations where the leaders decide. And several of those endorsements were accompanied by criticisms from members about the lack of a democratic process."