Union members react as Aerospace Machinists District 751 President Jon Holden (out of frame) announces that union members rejected a proposed Boeing contract and will go on strike, following voting results at their union hall in Seattle, Washington, on September 12, 2024. (Credit: JASON REDMOND/AFP via Getty Images)
A series of gains for America's unions made during Joe Biden's presidency are vulnerable now that Donald Trump is headed back to the White House.