However, two of his most prominent supporters -- talk show host Oprah Winfrey and Caroline Kennedy, daughter of President John F. Kennedy -- are scheduled to join Obama's wife Michelle at a get-out-the-vote rally tomorrow at a yet-to-be announced location in Los Angeles, a campaign aide said.
Obama will be endorsed Saturday by Los Angeles City Councilmen Richard Alarcon, Ed Reyes and Herb Wesson at a Van Nuys get-out-the-vote event
. Friday, Obama was endorsed by the Los Angeles Times, while Clinton received the backing of Los Angeles County Supervisor Gloria Molina.
The Times "strongly" endorsed Obama, calling him "the Democrat most focused on steering the nation toward constructive change."
Citing Obama's multi-racial background and a childhood partly spent in Indonesia -- the world's largest Muslim nation -- The Times said the Illinois senator's presence in the White House would most diffuse rising anti- Americanism around the world.
The Times also called Obama "a thoughtful student of the Constitution and an experienced lawmaker in his home state and, for the last three years, in the Senate."
It admitted that Obama and Clinton, whom it called "an accomplished public servant," are "a hairbreadth apart" on most major issues, including the war in Iraq and health care.
However, The Times sided with Obama, citing Clinton's 2002 vote to authorize the war.
"Clinton faced a test and failed," The Times said. "In the language of metaphor, Clinton is an essay, solid and reasoned; Obama is a poem, lyric and filled with possibility."
In its first presidential endorsements since 1972, The Times backed Arizona Sen. John McCain in Tuesday's Republican primary. The endorsements will appear in the Opinion section of Sunday's editions.
In making her endorsement, Molina cited her admiration of Clinton's "lifetime of work on behalf of children and families."
"I trust that she will deliver results when she is president," said Molina, who initially backed New Mexico Gov. Bill Richardson, a fellow Latino, in the race for the Democratic nomination. Richardson withdrew Jan. 10 following fourth-place finishes in the Iowa caucuses and New Hampshire primary.
"Her experience in helping to create economic opportunities for working people, ensure access to affordable health care and provide universal pre- kindergarten make her the best presidential candidate for the unbelievably challenging times we are living."
Molina was named as a national co-chair of the Clinton campaign.
"I am deeply grateful to have Gloria's support," Clinton said. "She has been a phenomenal leader for Los Angeles County and a strong voice for working families in California."