On December 31, 2007, Cantwell became the 10th senator to endorse Hillary Clinton for President of the United States.[70] Cantwell supported Clinton throughout the primary season,[71] but vowed to vote for the winner of the pledged delegates.[72] After Clinton's concession on June 7, Cantwell endorsed Obama.[73] At the Washington State Democratic Convention on June 15, Cantwell added: "I do want to see a strong Democratic woman in the White House ... That's why I'm so glad Michelle Obama will be the next first lady."[74]