Gillibrand served in the House representing the Hudson Valley from 2007 until 2009, when she filled the seat of Hillary Clinton, who resigned to become secretary of state. The feisty 50-year-old's early opposition to President Trump already has Democrats buzzing that she'll make a run for the White House in 2020. Should that happen, her successor would be picked by the governor, meaning neither Clinton nor Kennedy would even have to be elected.