Hillary Rodham Clinton had a simple message for her still loyal supporters: This election isn't about her. The former first lady ceded the nomination that was almost hers in a prime-time speech Tuesday to Democratic delegates, closing another chapter in a long, improbable political career that took her from supportive spouse to political powerhouse. She was warmly embraced by delegates split between herself and Barack Obama in the primary campaign. Any who were still angry over her loss were drowned out in applause when she opened her speech by declaring herself "a proud supporter of Barack Obama." She exhorted her backers - "my sisterhood of the traveling pantsuits," she called them, referring to her favored outfit on the campaign trail - to remember who was most important in this campaign.