The Teamsters union, representing over a million members, is considering not making an endorsement at all in this year’s presidential race — a move that would be an immense blow to President Joe Biden’s reelection campaign.

According to sources who spoke to Reuters, top Teamsters officials may decide not to endorse any candidate in the presidential race, which would be the first time since 1996 the union did not make an endorsement.

Though the Teamsters have a historical relationship with Democrats, the union endorsed Republican Presidents Richard Nixon, Ronald Reagan, and George H.W. Bush. Sources told Reuters that a Trump endorsement is still unlikely but that a Biden endorsement may also never come to fruition.

“No final decision has been made,” a spokeswoman for the Teamsters said.

On Monday evening at the Republican National Convention, Teamsters President Sean M. O’Brien made clear that the union had not yet settled on an endorsement and noted after his historic speech that he has yet to be invited to speak at the Democratic National Convention.

“It’s an honor to be the first Teamster in our 121-year history to address the Republican National Convention,” O’Brien said at the RNC.

“President Trump had the backbone to open the doors to this Republican convention, and that’s unprecedented. No other nominee in the race would’ve invited the Teamsters into this arena,” O’Brien said. “… I think we all can agree, whether people like him or they don’t like him, in light of what happened to him on Saturday, he has proven to be one tough SOB,” he said to cheers from the RNC crowd.

John Binder is a reporter for Breitbart News. Email him at jbinder@breitbart.com. Follow him on Twitter here.