The Hill’s Changemakers: Sean O’Brien, Teamsters president

International Brotherhood of Teamsters General President Sean O’Brien has had a wicked wild year.  

He made history this summer as the first Teamsters head to speak at the Republican National Convention, a move that drew criticism from both sides of the aisle and other labor leaders who coalesced behind Democrats.  

“Backstage was tense,” said O’Brien, a lifelong Democrat and former heavy-equipment driver with Teamsters Local 25 in Boston. “It was little intimidating, I’m not gonna lie, and I don’t get intimidated.”  

But facing down a Republican trifecta in Washington, his union is now well-positioned to navigate what is expected to be a perilous period for organized labor, having carved inroads with President-elect Trump, Vice President-elect JD Vance and a handful of GOP allies on Capitol Hill including Sen. Josh Hawley (Mo.).  

O’Brien has even patched things up with Sen. Markwayne Mullin (R-Okla.), who challenged him to a brawl during a hearing last fall.  

“I don’t consider myself a changemaker. I’m a realist. I want to build bridges, build relationships and make sure that we work together when we can work together on issues that are important,” O’Brien told The Hill.  

The strength of those relationships will be put to the test during brewing battles over potential national right-to-work legislation, which the union opposes, and the PRO Act, which would expand protections related to employees’ rights to organize and collectively bargain.  

The Teamsters was one of the few major unions not to endorse Vice President Harris — ultimately declining to endorse a presidential candidate for just the third time since 1960 — after a majority of members said they preferred Trump and neither candidate could “commit” on the union’s core issues.  

O’Brien, who has bucked the notion that unions should automatically back Democrats, encouraged the party to “reassess and reinvest” in the wake of the 2024 election.  

Amid the politicking and jockeying, however, he said his proudest professional accomplishment was winning the election to represent the Teamsters over the past 2 1/2 years, the first change in the union’s leadership since 1998.  

“What I’m most proud of is the ability to serve 1.3 million members in a capacity where we are influential once again, and we are also embraced by many, many factions that wouldn’t embrace us prior,” O’Brien said.  

—Updated Dec. 18 at 10:12 a.m.