DENVER — Maya Soetoro-Ng, U.S. Sen. Barack Obama's younger sister, honored their mother last night as a sturdy woman and an eternal optimist who challenged them to explore.

On a night when Obama's life story and the people he loves had a national audience, Soetoro-Ng told delegates to the Democratic National Convention that she wished their mother was alive to see his presidential campaign.

Ann Dunham died in 1995, before Obama's political success, and her ashes were scattered near the Halona Blowhole.

Obama, who was born in Hawai'i and graduated from Punahou School, was raised by his mother and his grandparents — Stanley and Madelyn Dunham — after his father, Barack Sr., went to Harvard University and then returned to Kenya.

"When we were young, our family didn't have much in the way of wealth, but what we did have was far more important," Soetoro-Ng said. "We had people who made us believe that with a little imagination, we could dream the improbable.

"That through hard work, we could accomplish the extraordinary. That through the power of education, we could propel ourselves to a future far more promising than our circumstances led us to expect.

"Perhaps, most importantly, we had our mother."

Like their mother, she said, her brother has opened her mind and spirit to a broader world.

Soetoro-Ng, a history teacher at La Pietra Hawaii School for Girls, said she has tried to share with her students the "bountiful opportunity" that her brother sees for the nation.

"I wanted them to know that they had belonged to something greater. I wanted them to imagine wider, dream bigger and reach higher. To realize that they had more power than they knew," she said.

"That is what this nation gave to Barack, and that is what he wants for his daughters and my daughter, and every single child in this country."

U.S. Rep. Neil Abercrombie, D-Hawai'i, said he calmed Soetoro-Ng after she came off the stage and said how nervous she was from the moment.

"I think her mother would have been so proud of her. You can imagine the pressure," the congressman said.

Abercrombie, who knew Ann Dunham, said she studied anthropology because of her interest in humanity and her curiosity about the world. She has been described as a free spirit but the congressman said there was also a sense of purpose and responsibility.

"Both her son and her daughter have grown up to be people of the world with a deep connection to people," the congressman said.

SIMILAR BACKGROUNDS

Soetoro-Ng's father is Lolo Soetoro, Dunham's second husband, who was from Indonesia. Dunham had met Soetoro, like she had met Obama's father, as a student at the University of Hawai'i.

Michelle Obama, Barack Obama's wife, also referred to Dunham and Barack Obama's grandparents in her remarks to the convention last night.

Michelle Obama, who grew up on the south side of Chicago to a blue-collar father and a stay-at-home mother, said their backgrounds show how the American dream endures.

"What struck me when I first met Barack was that even though he had this funny name, and even though he'd grown up all the way across the continent in Hawai'i, his family was so much like mine," she said.

"He was raised by grandparents who were working-class folks just like my parents and by a single mother who struggled to pay the bills, just like we did. And like my family, they scrimped and saved so that he could have opportunities they never had themselves."

Soetoro-Ng has blossomed over the past year from a somewhat awkward, reluctant public speaker into a popular campaign surrogate.

Soetoro-Ng does not speak in sound bites and, as a teacher, is fond of longer, deeper and more philosophical answers to questions about her brother.

In many of the profiles of the Illinois senator that have appeared in the national and international media, it has often been his sister who has spoken for the family and provided the most telling glimpses into his childhood.

Kari Luna, the vice chair of the Democratic Party of Hawai'i, recalled how she hosted an informal gathering at her home on Maui in May 2007 so Soetoro-Ng could get her feet wet as a campaigner.

"She absolutely has a connection with people," said Luna, the director of student support services programs at Maui Community College.

"The great thing about Maya is she is so real. She tells a lot of great stories that make us feel a lot closer to their family and to get to know them more on a personal level, which I think is very important, culturally, in Hawai'i."

'VERY PERSONAL LEVEL'

Andy Winer, the state director of Obama's campaign, said Soetoro-Ng's own story can help draw in voters. As a working mother from a mixed race background who has a Ph.D., she can be an example, especially for young women in the Islands.

"When she talks about Barack, she is able to speak on a very personal level, how it was that they had a real struggle," he said.

Winer said Soetoro-Ng would likely campaign for Obama on the Neighbor Islands and O'ahu and could appear at the party's traditional rally in Hilo the night before the Sept. 20 primary. She is expected to campaign on the Mainland for her brother in October.

Gay Chinen, the dean of La Pietra's upper school, said some teachers had planned to watch Soetoro-Ng's speech with their students in class yesterday while others will record it and bring it in to discuss later.

Soetoro-Ng has had to take time off from teaching for the campaign, and her profile has risen with the media attention, but Chinen said the experience has not been a distraction for the private school.

"She's a really lovely, lovely person," Chinen said. "She's very well-liked by her students."

Soetoro-Ng's husband, Konrad Ng, an assistant professor at UH-Manoa's Academy for Creative Media, has also gotten involved in the campaign.

Konrad Ng has blogged on Obama's campaign Web site, and some of his students have produced a new grassroots advertisement that will likely appear on Obama's Web site and YouTube channel.

The one-minute ad will also likely be shown here this week at an Asian and Pacific Islander caucus. The ad depicts scenes from family life — with themes of preserving small businesses, caring for the elderly and recognizing military sacrifice — as Obama's speech this month at a public rally in Hawai'i plays in the background.

Mark Wolf, a UH senior, and his three partners hope the ad will help launch their new Web-based film production project.

"We all feel that positive change is something that we need right now," Wolf said.