International Brotherhood of Teamsters president Sean O’Brien is in hot water with his own members after giving a speech at the Republican National Convention this week. And it could now cost him his position. According to In These Times labor reporter Kim Kelly, O’Brien is drawing a challenger in John Palmer, the union’s VP-at-large, who tore O’Brien to shreds in an announcement of his candidacy for the union’s leadership election in 2026, urging members to vote for him to “send Sean O’Brien back to the truck.” The Teamsters is one of America’s largest umbrella union organizations, representi…