A local union branch of New Hampshire state and local employees said Sunday that it had voted to endorse Senator Bernie Sanders of Vermont for the Democratic presidential nomination, another labor endorsement for a candidate whose political stock continues to rise less than a month before the Iowa caucuses.
The endorsement, which will officially be made on Monday, is particularly notable because the union chapter, SEA/SEIU Local 1984, has acted separately from its national affiliate organization, the Service Employees International Union. That group, which represents about two million workers nationally, has remained neutral in the endorsement process up to this point, balancing relationships with multiple candidates and regional concerns that differ across local chapters.
But the New Hampshire chapter wanted to use its political firepower to back Mr. Sanders in time for the state’s first-in-the-nation primary, Rich Gulla, the local president, said in a statement. About 10,000 workers across the state are represented by the union’s collective bargaining contract.
The chapter also voted to endorse Mr. Sanders during the 2016 presidential election — even as the national organization backed his rival and the eventual Democratic nominee, Hillary Clinton.
“Senator Sanders has taken the time to stand with us on multiple occasions,” Mr. Gulla said, citing a joint news conference that state workers held with Mr. Sanders in December. “This type of unwavering dedication to New Hampshire’s workers means that we can trust him to have our backs. For these reasons and more, we are thrilled to endorse Senator Bernie Sanders for president.”
Both the 2016 primary and general elections for president disrupted many labor organizations and the political process that governs their endorsements. Several groups experienced a split between rank-and-file members and union leadership, emblematic of the larger grass-roots and establishment split that has roiled both political parties in recent years.
As a consequence, many labor organizations have been more transparent, democratic and prudent about their endorsement process in this election cycle. At SEIU, which endorsed Mrs. Clinton in November 2015, well before the Iowa caucuses, there are few plans to back an individual candidate before early-state voting begins in 2020.
Leaders have instead established a lengthy interview process for candidates that includes embracing a “Unions for All” agenda and walking for a day with SEIU members. According to union organizers who were familiar with Local 1984’s process, the national group’s board was aware that the local was set to endorse Mr. Sanders ahead of the state primary, and did not discourage it from doing so.
It is unclear whether other local chapters will now become more involved in the presidential race. In a statement, Sara Lonardo, a spokeswoman for the national union, said, “SEIU members are paying close attention to this race and are still evaluating candidates on their plans to put power back in the hands of working families and give all working people the ability to join together in unions, no matter where they work”
Ms. Lonardo said. “We will continue engaging our members nationwide to determine who they see as the best candidate for our union to endorse.”
Mr. Sanders has increasingly gathered grass-roots support in recent months, as the Democratic Party’s left wing has rallied around his candidacy. In October, Mr. Sanders announced endorsements from popular House Democrats including Ilhan Omar of Minnesota, Rashida Tlaib of Michigan and Alexandria Ocasio-Cortez of New York. He has also gained the backing of labor organizations like National Nurses United and left-wing advocacy groups including the Center for Popular Democracy Action and People’s Action.
Last week, he earned the backing of two progressive issue-focused groups: Dream Defenders, a Florida-based collection of activists that focuses on criminal justice reform, and the Sunrise Movement, a group made up of young climate activists.