Obama: 'This time is different'

CHICAGO (CNN) - Sen. Barack Obama took the stage to the strains of U2's "It's a Beautiful Day" Tuesday night, claiming that "our time has come ... and change is coming to America."

"There is one thing on this February night that we do not need the final results to know," he said, noting that all the votes on Super Tuesday had not been counted. "Our time has come."

"What began as a whisper in Springfield has swelled to a chorus of millions calling for change," Obama said. "This time can be different because this campaign for the presidency of the United States of America is different."