LOS ANGELES—This could be big.

Maria Shriver, the first lady of California (wife of Republican governor Arnold Schwarzenegger) just endorsed Barack Obama on a stage here at an event at UCLA with Oprah Winfrey, Michelle Obama and her cousin Caroline Kennedy.

Shriver, the daughter of Eunice Kennedy, John F. Kennedy's sister, said that above her computer in her office she keeps a quote from Eleanor Roosevelt that said “Do one thing every day that scares you."

“Eleanor, wherever you are,” Shriver said. “This is my one thing for today.”

Echoing Winfrey, she said that she was following her “own truth” as she spoke admiringly of Obama as the candidate who could best unite the nation.

“I’m standing here because I want to be here,” said Shriver. “I wasn’t on the schedule and I thought to myself when I woke up this morning, there is no place I should be but right here today.”

She said her decision was literally a last minute one, and that this morning, her daughter, a first time voter, said to her “If you think you can help, if you think you can change just one person if you think you can make a difference, then go.”

“I am here today as a woman and as a Californian,” she said and added, “The more I thought about it. If Barack Obama was a state he’d be California.” She said he was diverse, smart, open, independent, a dreamer and a leader.

“California has a primary that has been moved up, it is at the epicenter of change, we can lead, we can lead this country,” said Shriver. “I would ask you to go out and follow your heart, and remember that so goes California, so goes the nation.”