Jimmy Kimmel delighted in the unraveling of President Donald Trump's massive party for America's 250th birthday, a celebration that has devolved into what the late-night host called a monument to MAGA incompetence.The event, organized by Freedom 250 and scheduled for the National Mall from June 27 to July 10, was billed as a nonpartisan commemoration of the nation's 250th birthday. But it's suffered an exodus as multiple stars pulled out, claiming they had no idea of its political connections.Headliner country star Martina McBride became the most prominent act to ditch the event, writing on X Thursday that the nonpartisan framing she'd been given "turned out to be misleading." The Commodores, Young MC, and Morris Day & The Time have also quit the event.What remained, Kimmel told his audience, was a lineup "like Coachella for bands that hired their cousin as their tour manager" — a roster headlined by Flo Rida, Vanilla Ice, and Bret Michaels.Then there's the Milli Vanilli situation.The German duo that was famously exposed as lip-synching in a 1990 scandal is scheduled to perform, though one of its two public frontmen is now dead. The actual studio vocalists behind the group, twin sisters Jodie and Linda Rocco, said they were never contacted by organizers. A statement from the Milli Vanilli camp confirmed they had no involvement and warned that anyone appearing under the name should be regarded as a tribute act with no authentic connection to the group."How can someone pretend to be Milli Vanilli," Kimmel asked, "when Milli Vanilli was pretending to be Milli Vanilli?"He added, "What a concert this is gonna be," he said. "Everything they do, they screw up. They cannot do anything."The devolving concert has left Trump's allies furious.Trump ally and former head of the Kennedy Center, Richard Grenell responded to McBride's announcement with the comment, "You've always been a woke lefty,"Fox News host Todd Starnes on X, “Since you are clearing the air, how about explaining why you performed at the White House during the Obama regime? Or during Bill Clinton’s scandalous presidency?”