At would’ve been ludicrous to think that Oprah Winfrey would become Oprah Winfrey following her first talkshow on Jan. 2, 1984.

She took over as host of a low-rated half-hour morning show in Chicago that was barely staying afloat. Suddenly, however, the WLS skein gathered enough steam to pass local favorite Phil Donahue. Soon, it was expanded to an hour, renamed “The Oprah Winfrey Show” and, following a syndication deal with King World, was broadcast nationally.

“She changed the way women watch daytime,” says Terry Wood, president of creative affairs and development at CBS TV Distribution and a longtime friend of Winfrey’s. “They turned on the television and saw themselves in her. She gave them different ways to experience information about your life.

“She was comfortable letting them in, and what Oprah has done is to let viewers experience her evolution. She’s shared so much of her life — her passions, fears and excitement — that’s it been the basis for a strong relationship.”

Her daytime dominance is unprecedented and shows little sign of decline. While her ratings and everyone else’s are down in the daypart, she’s drawing more viewers now than five years ago.

And talk about consistency? “Oprah” is closing in on being the top-rated talkshow for 500 consecutive weeks.

The name Oprah has become a brand in itself, and her associations with Dr. Phil McGraw and Rachael Ray — after repeatedly having them on the show as guests — have helped raise their profiles to become talkshow successes on their own. Next year, “Dr. Oz” becomes the next talker to try to find its footing with Winfrey’s built-in credential.

Not satisfied with just helping to kickstart a couple new shows, she is creating an entirely new slate: The Oprah Winfrey Network will begin in 2009 in 70 million homes and is in the midst of planning a programming lineup. Winfrey also is in the second year of a deal with XM Radio.

In 2008, Winfrey’s influence crossed over into the political arena when she endorsed Sen. Barack Obama for president early in the race. “For a decision like that, I don’t think she was looking around the political landscape. That decision was very personal with her,” Wood says. “This man resonated with her.”

When Larry King asked Winfrey what her endorsement meant to the Obama campaign, she said, “I think that my value to him, my support of him, is probably worth more than any check.”