I first met Dave McCormick in 2023 during a party for his book, Superpower in Peril, hosted at the offices of a white-glove law firm in Philadelphia. At the time, he had recently stepped down as the C.E.O. of Bridgewater Associates, one of the world’s largest and most secretive hedge funds, and was clearly telegraphing his continued interest in higher office. The firm’s partners included both Republican and Democratic donors, most of them searching for clues about whether McCormick, a decorated military veteran with Princeton and Bush administration accolades on his résumé, was going to make another run for Senate after losing the 2022 G.O.P. nomination to Dr. Mehmet Oz.