The Teamsters on Wednesday declined to endorse a candidate for president, the first time in decades that the union hasn't backed a candidate in the presidential election.

"Neither major candidate was able to make serious commitments to our union to ensure the interests of working people are always put before Big Business," Teamsters General President Sean O'Brien said in a statement.

He added, "We sought commitments from both [former president Donald] Trump and [Vice President Kamala] Harris not to interfere in critical union campaigns or core Teamsters industries—and to honor our members’ right to strike—but were unable to secure those pledges."

The union's decision comes two days after senior leaders met with Harris as they weighed whom to endorse.

The Teamsters, which represents truck drivers, freight workers and others, held similar meetings with Trump and President Joe Biden when he was still seeking re-election.

The union, which at 1.3 million members is one of the largest in the world, collected input on an endorsement from its members through straw polling and a QR poll from a code printed on a union magazine, a vice president at large of the union, John Palmer, said.

On Wednesday, the union released the results of their survey, which was conducted after Biden dropped out of the race. It found that almost 60% of rank-and-file union members preferred to endorse Trump, while 34% backed Harris, according to an electronic member poll. A phone poll indicated similar margins, with 58% supporting Trump and 31% supporting Harris.

The union has not released the number of poll participants or the margin of error.

The Teamsters have for decades endorsed Democratic presidential candidates. The union supported Hillary Clinton in 2016 and Joe Biden in 2020. They also backed Barack Obama in both of his presidential runs, John Kerry in 2004 and Al Gore in 2000.

In an email Wednesday, the Trump campaign highlighted the Teamsters polling.

"While the Teamsters Executive Board is making no formal endorsement, the hardworking members of the Teamsters have been loud and clear— they want President Trump back in the White House!" said campaign spokesperson Karoline Leavitt in a statement. "These hardworking men and women are the backbone of America and President Trump will strongly stand up for them when he’s back in the White House."

The former president addressed the union's decision not to endorse a candidate when talking with reporters on Wednesday, saying that it is "a great honor."

"The Teamsters carry a lot of weight. The Democrats cannot believe it," Trump said. "Look, it was always automatic that Democrats get the Teamsters, and they said, 'We won’t endorse the Democrats this year,' so that was an honor for me."

Harris campaign spokesperson Lauren Hitt pointed to local Teamsters chapters that endorsed the vice president.

“The Vice President’s strong union record is why Teamsters locals across the country have already endorsed her — alongside the overwhelming majority of organized labor,” Hitt said in a statement. “As the Vice President told the Teamsters on Monday, when she is elected president, she will look out for the Teamsters rank-and-file no matter what — because they always have been and always will be the people she fights for.”

Over the course of his presidency, Biden has promoted his support for organized labor and has frequently weighed in on disputes between union workers and corporate leaders. In 2021, he expressed support for the right to unionize in a direct-to-camera video as Amazon workers in Alabama were about to vote on whether to organize.

Then-Teamsters president James P. Hoffa in 2021 credited Biden with including an $83 billion pension-fund bailout in the American Rescue Plan Act, which boosted the Teamsters' Central States pension fund.

In 2023, Biden became the first sitting president to join a picket line when he visited striking autoworkers in Michigan.

But despite calling himself “the most pro-union President leading the most pro-union administration in American history,” Biden drew criticism from organized labor two years ago when he worked with Congress to pass a law that averted an impending rail strike.

The law forced union workers to accept a union contract that had been brokered by the Biden administration. At the time, four of the 12 unions involved had rejected the deal.

As he signed the legislation, Biden called it “a tough [vote] for me,” but cited the need “to keep the supply chains stable around the holidays.”

The International Association of Fire Fighters is the most prominent union that has not yet endorsed a presidential candidate this year. The union endorsed Biden in 2020.

The AFL-CIO, which represents dozens of unions and millions of workers, and the United Auto Workers union have each endorsed Harris.