The president of the Teamsters union has asked for speaking slots at both the Republican and Democratic national conventions, at a time when President Biden and former President Donald J. Trump have pressed for support from rank-and-file members of organized labor.
The move by Sean O’Brien, the president of the International Brotherhood of Teamsters, underscores the fact that his group, unlike other influential umbrella unions that have backed Mr. Biden in the 2024 election, has yet to endorse in the presidential race. Mr. O’Brien has made clear he is delaying a decision until later this year.
Kara Deniz, a spokeswoman for the Teamsters union, confirmed that Mr. O’Brien, through aides, has told officials working on both conventions that he would be interested in speaking at their dayslong nomination events. The Republicans will hold their convention in Milwaukee in July, and the Democrats will hold theirs in Chicago in August.
It would be unusual in the current fractious political climate for someone to speak at both conventions.
Over the course of the year, Mr. O’Brien has invited several presidential candidates, including Mr. Biden, Mr. Trump and independent candidates like Cornel West and Robert F. Kennedy Jr., to speak before his group. But Mr. O’Brien has what people close to Mr. Trump believe is a developing relationship with the former president.
The Teamsters is one of the country’s largest labor unions, with 1.3 million members in sectors like trucking and manufacturing. The A.F.L.-C.I.O. and the United Automobile Workers have backed Mr. Biden, and Shawn Fain, the president of the U.A.W., has been harshly critical of Mr. Trump.
Mr. O’Brien, however, has appeared more open to the former president.
Mr. O’Brien had a private meeting with Mr. Trump at the beginning of the year at Mar-a-Lago, shortly before the Iowa caucuses that the former president won handily, setting him on a path to become his party’s nominee for a third time.
The following month, the Teamsters gave $45,000 to both the Republican and Democratic convention funds, with officials saying the goal was to make sure its rank-and-file members are heard at the convention.
Mr. Biden has described himself as the most pro-labor president in history. And in 2020, he cut into what had been Mr. Trump’s advantage with working-class white voters in the 2016 presidential campaign against former Secretary of State Hillary Clinton. That year, Mr. Trump’s appeal to voters in the Rust Belt states of Wisconsin, Michigan and Pennsylvania was key to his victory.
Also that year, some of Mr. Trump’s allies, including Paul Manafort, his onetime campaign chairman, tried working connections in the labor movement to see if they could peel off support for Mrs. Clinton from organized labor.
This year, as Mr. Biden has struggled in the Sun Belt swing states, such as Arizona, his path through white working-class states in the Rust Belt is seen as key.
Even absent an endorsement, having Mr. O’Brien at the Republican National Convention would be politically useful to Mr. Trump, who often highlights relationships to score political points. The Teamsters endorsed Mr. Biden in 2020, although their support came relatively late in the general election campaign, well after it was clear that the then-candidate would be the presumptive Democratic nominee.
A spokeswoman who represents both the Trump campaign and the Republican National Committee did not respond to a request for comment about whether the GOP will grant Mr. O’Brien a speaking slot.
Kevin Munoz, a spokesman for the Biden campaign, did not address whether the Democrats will give Mr. O’Brien a slot.
“There’s only one candidate in this race fighting for American workers and creating good-paying union jobs here at home, and that’s President Biden,” Mr. Munoz said, saying that Mr. Trump “has spent his entire life fighting against workers’ rights” and that Mr. Biden “will continue to work to earn the Teamsters’ support.”
Mr. O’Brien was elected president of the union on a wave of reformist energy in 2021. But unlike some umbrella unions that have backed Mr. Biden, Mr. O’Brien has a number of members in southern states who support the former president. And whatever his personal relationship with Mr. Trump, there is likely a benefit to Mr. O’Brien with his own members in being seen as open to talking to Republicans.