Nancy Pelosi introduced Obama at a San Fran fundraiser calling him, "a leader that God has blessed us with at this time."
According to the pool report, Obama followed that humble introduction with his own modest pronouncement: "I will win. Don't worry about that," he told the crowd of 1,300. Source.
Humility and grace should be prerequisite of any nominee! Remember when Hillary said the same thing to Katie Couric in her interview last year; "I will win, I am 100% positive". Watch the video and see how arrogant she was and that cost her.