Hedge fund manager Stephen Mandel and his wife Susan are a billionaire power couple that has a history of springing into action come election season. Before the 2024 presidential contest, they hosted Joe Biden for a private fundraising dinner in Greenwich, Connecticut. Kamala Harris, Hillary Clinton, and John Kerry are other beneficiaries of the $84 million that the Mandels have sprinkled to Democratic campaigns over time, according to Federal Election Commission records. Now, the couple is