 Act One, Fate of the Union. For all the people who'd rethought their feelings about Donald Trump at the Republican National Convention in Milwaukee this week, there was one guest for whom the rethink has been especially dramatic, and that's Sean O'Brien. A lifelong Democrat from Massachusetts, Sean O'Brien is the head of the Teamsters Union. 1.3 million truck drivers, rail, air, all transportation, delivery workers, lots of jobs. They endorsed Biden in 2020.