Hillary Rodham Clinton promised to be a champion for everyday Americans on Sunday as she kicked off a long-awaited second run for the White House as the commanding Democratic front-runner.

"Everyday Americans need a champion. I want to be that champion," Clinton said in a video released on the Internet that announced her run.

"Americans have fought their way back from tough economic times, but the deck is still stacked in favor of those at the top," she said.