Cantwell supported Clinton throughout the primary season , but vowed to vote for the winner of the pledged delegates .
On December 31 , 2007 , Cantwell became the 10th senator to endorse Hillary Clinton for President of the United States .
Cantwell supported Hillary Clinton throughout the primary season , but vowed to vote for the winner of the pledged delegates .
On December 31 , 2007 , Cantwell became the 10th senator to endorse Hillary Clinton for President of the United States .