WASHINGTON (CNN) -- Popular talk-show host Oprah Winfrey reiterated her support of Sen. Barack Obama's, D-Illinois, presidential bid Tuesday, and told CNN's Larry King she will never seek political office herself.

Winfrey, who has never endorsed a presidential candidate in the past, said she chose to support Obama this time because she knows "what he stands for."

"I know him personally," Winfrey said. "I think that what he stands for, what he has proven that he can stand for, what he has shown was worth me going out on a limb for, and I haven't done it in the past because I haven't felt that anybody -- I didn't know anybody well enough to be able to say, 'I believe in this person.'"

When asked if she would ever run for an office herself, the popular talk-show host said she is able to make more of an impact in her current job than she could in any political post.

"You know that is not going to ever happen," she said of a potential political bid. "I feel that the platform that I hold, the chair in which I get to sit in every day and speak to the world, is of far more value to me than any political office could be."

"Value in that I get to speak to people's hearts and get to connect with people all over the world," she added.