KEY POINTS:
One of the big political questions of the hour is whether Oprah Winfrey can help turn Barack Obama into the first African-American President of the United States.
This weekend Winfrey is throwing open the gates of her 17ha Promised Land estate in Montecito, California, for her first political fundraiser.
She will welcome about 1500 guests to her home and expects to raise about US$3 million ($4.3 million) for Obama's already overflowing coffers.
By some assessments Winfrey is already the most influential woman in the world: her daytime TV show, with 8.4 million viewers, is the highest rated talkshow in history.
She recently launched her own satellite radio channel. She is the wealthiest and most philanthropic African-American ever, and her book club is a major force in publishing.
In fact, there are many who wish Oprah herself would run for President, but she has already ruled it out.
In May she told her viewers that she was backing Senator Obama in what was seen as a major boost for his campaign. But she is talking about going out on the stump and bringing her extraordinary branding expertise to the Obama White House run.
The prospect of Winfrey turning up with Obama would broaden the appeal of his already electrifying public events.
This weekend could be the start of that beautiful friendship. As with most political events, the candidate will speak briefly and then mingle with the crowd. But only a select group will have access to Winfrey, and her home will remain off limits.
Tickets are already sold out at US$2300 each, which is the maximum donation for Obama's primary campaign. Hollywood stars including Will Smith, John Travolta, Jamie Foxx and Halle Berry are on the guest list, and the music legend Stevie Wonder and the gospel singer BeBe Winans are to entertain the crowd.
When the party is over, the expectation is that Winfrey will appear in television ads and make special public appeals, although representatives of Obama and Winfrey have declined to comment.
"My money isn't going to make any difference," Winfrey recently told CNN's Larry King. "My value to him - my support of him - is probably worth more than any other cheque that I could write."
Winfrey first met Obama and his wife, Michelle, before he ran for the US Senate in 2004 and they have remained close ever since.
Hollywood actor and former US senator Fred Thompson, 65, yesterday declared his candidacy for President. His announcement had been expected for months.
Winfrey's World
* TV show: 8.4 million viewers daily.
* Website: 2.3 million unique viewers a month.
* Magazine: 2 million readers a month.
* Newsletter: 420,000 weekly subscribers.
* Oprah alerts by email: 360,000 subscribers.
- Independent , Reuters