Doug Emhoff was tasked with getting Taylor Swift to stump for his wife, Kamala Harris, on her ill-fated 2024 presidential campaign — but failed to seal the deal,according to a new book. Rumors swirled on Election Day eve that thechart-topping pop starwould perform, or at least make an appearance, at the then-vice president's final rally in Philadelphia, near Swift's hometown of West Redding, Pa. The "Love Story" singer, however, had apparently already rebuffed the former second gentleman's efforts to get her to do anything more than endorse the failed Democratic presidential nominee, journalists Josh Dawsey, Tyler Pager and Isaac Arnsdorf explain in their forthcoming book,"2024: How Trump Retook the White House and the Democrats Lost America." "Swift proved to be a special challenge," the authors of the new book, due out Tuesday, explained. "Staffers who worked on celebrity appearances were instructed not to make any outreach to her universe; Doug Emhoff was handling it." Emhoff, a former Los Angeles entertainment lawyer, had a prior relationship with Swift's attorney, Doug Baldridge, and had reached out to him "to convey that the campaign would appreciate any efforts the pop star could make to help Harris" before Swift's surprisepost-debate endorsement, the book claimed. Baldridge's devastating response to the Harris camp was: "Swift would do what Swift thought was best." "Nothing more than the endorsement ever materialized," the authors noted. Philadelphia rally-goers were instead treated tospeeches and performancesby Fat Joe, Lady Gaga, Ricky Martin, The Roots, will.i.am, and Oprah Winfrey. Every morning, theNY POSTcastoffers a deep dive into the headlines with the Post's signature mix of politics, business, pop culture, true crime and everything in between.Subscribe here! The Harris campaign put on severalstar-studded concertsin the days leading up to the former vice president's Election Day defeat. Katy Perry, Christina Aguilera, Megan Thee Stallion, Bruce Springsteen, Jon Bon Jovi, 2 Chainz and Mumford & Sons were among other artists and musical acts that lent their talents to the Harris campaign in an apparent effort to get low-propensity voters out to the polls. Grammy Award-winning artists Beyonce, Cardi B and Jennifer Lopez also appeared on the stump for Harris, but didn't perform —upsetting some Harris supporters. The series of election eve concerts alone reportedlyset the campaign back $20 million. The performances were held in swing states that all went for President Trump the following day. "Privately, some campaign staff raised concerns that the major rallies may not be worth the millions of dollars they cost to stage or the staff investment," the authors stated, noting that "There was scant evidence that the rallies were persuading voters or necessarily boosting turnout."