Vice President Kamala Harris joined a meeting with the International Brotherhood of Teamsters Monday in hopes of getting the union's endorsement, Politico reported.
The Teamsters, which has 1.3 million members, typically endorses the Democrat nominee after the party convention.
"The sooner the better," Sen. Bernie Sanders, I-Vt., told Politico about a possible Teamsters endorsement.
Teamsters General President Sean O'Brien spoke at the Republican National Convention in July, though he has not endorsed former president Donald Trump. Trump met with the Teamsters in July and President Joe Biden met with them in March, when he was still the presumptive Democrat nominee, Politico reported.
After O'Brien spoke at the Republican National Convention he was denied a chance to speak at the Democratic National Convention, Politico said.
At the GOP Convention, O'Brien praised GOP lawmakers and criticized corporate America, though he later accused Trump of "economic terrorism" after Trump told Elon Musk he supported firing workers who go on strike.
The AFL-CIO and United Auto Workers have endorsed Harris. The Teamsters National Black Caucus has also endorsed Harris.
A poll taken before Biden dropped out showed 45% percent of Teamsters members were supporting Biden while one-third were supporting Trump.
Sen. Josh Hawley, R-Mo., told Politico he doesn't think a Teamsters endorsement will have any impact on the race.
"If you don't have an opinion on Donald Trump, I mean — who doesn't have any opinion on Donald Trump?" Hawley asked. "A Teamsters endorsement for Trump would absolutely matter, I think, but it's not as if you've never heard of him, 'Like you should really check out this guy named Trump.' No, they all know who he is. So, I don't know if it's as important. You're not starting from zero."
Rep. Ro Khanna, D-Calif., told Politico endorsements from unions can help Harris make inroads with voters without a college degree. Harris trails Trump by 17% among people without a college degree, according to a New York Times/Siena College poll.
"When we look at the union vote, that's what's saving us," said Khanna. "We're not doing well in general with men without college degrees, but we're doing much better with union voters."