What’s the value of a celebrity endorsement in a political campaign? In the case of Oprah Winfrey and Barack Obama, about 1 million votes.

Oprah Winfrey might be losing her touch.

To a degree unlike any other city in America, Chicago is identified with its black elite. Locals joke that you can find more black millionaires per square foot at the Chicago Urban League’s annual dinner than you can anywhere in the world.

Brad Pitt is unlikely to quit his day job, especially with a houseful of Jolie-Pitt munchkins. And judging from the picture of partner Angelina’s much talked about “bump” during this past weekend’s Independent Spirit Awards, child number five may be on the way.

Last week California Governor Arnold Schwarzenegger endorsed Republican John McCain for president. Sunday, the governor’s wife, Maria Shriver, endorsed Democrat Barack Obama.

Celebrity support, always important in national campaigns, is likely to play an increasing role in the high-cost, heated presidential campaign of 2008.

When it comes to good-looking supporters, Barack Obama leads the pack, with Scarlett Johansson, Jennifer Aniston, Halle Berry, Jamie Foxx, and George Clooney. And of course, there’s his powerhouse stumper, Oprah Winfrey.

Hillary Clinton is backed by a slightly older, more established, show business crowd which includes Chevy Chase, Danny DeVito, Rob Reiner and Steven Spielberg.

Move over Martha Stewart because Rachael Ray’s souffle is rising.

In a year that saw the share price of the once-mighty Martha Stewart Living Omnimedia sag precipitously, Stewart dropped off Fortune’s list of the 50 Most Powerful Women.

Ray, meanwhile, strengthened her claim as America’s new domestic diva in 2007. She signed a new contract with Food Network, and pulled down $16 million for her thriving year-old network television talk show.

Not every candidate would welcome an endorsement from a guy known as “Meathead.”

But when that guy is Rob Reiner — Meathead in the 1970s television hit All in the Family — you take the endorsement and run.

Reiner, the 62-year-old actor, director, comedian and political activist, and one of the most connected people in Hollywood and Democratic politics, came out for Hillary Rodham Clinton in September.

Oprah Winfrey just got a little richer.

NBC Universal announced today that it would buy Oxygen Media, the cable TV network founded by Winfrey, CEO Geraldine Laybourne and three TV producers, for $925 million.

The purchase is yet another indication from NBC Universal that it is targeting women viewers. Other Universal properties with significant female audiences include iVillage, Bravo and the Today show.

Oprah Winfrey and Maya Angelou are the best of friends.

But, as the New York Times notes today, they’re likely to avoid talking politics.

Winfrey endorsed Obama on “Larry King Live” in May, and is planning a fundraiser for him at her California home. Angelou is featured on Clinton’s web site, backing her candidacy and describing the importance of women running for high office.