Likening Democratic U.S. presidential candidate Sen. Barack Obama to a political “trailblazer,” singer Barbra Streisand has become the latest Hollywood celebrity to join the Obama campaign bandwagon, switching from her past support of Sen. Hillary Clinton.

“Barack has awakened in many of us the notion that we can again be hopeful, enabling us to believe that we are capable of lifting our brothers and sisters out of poverty, of providing quality education for all our children, of ending this unjust war in Iraq and bringing our troops home safely,” Streisand wrote on Tuesday in a posting on her Web site, http://www.barbrastreisand.com/.

“He’s reminded us ‘yes we can’…we can make the transition from fossil fuels to green energy; we can take care of our elderly and make sure that good healthcare is not just a perk for a few, but a right for every man, woman and child,” she said. ”We are experiencing not just a presidential campaign, but a movement; a movement of inspired young people who have been cynical about politics for too long.”

Since narrowly defeating Clinton at the end of the U.S. primary elections in June, Obama, a Democrat from Illinois, has picked up numerous endorsements. Clinton, a U.S. Senator from New York, has appeared with him in a show of Democratic party unity. Last week, Obama held a fundraiser in Los Angeles that raised some $4 million to $5 million, and several Hollywood stars such as Dennis Quaid and Samuel L. Jackson were there.

Streisand, of course, is a major Hollywood celebrity and fundraiser for Democrats. Yet, celebrity endorsements have a mixed track record in helping candidates, the experts say. Republican candidate Sen. John McCain also has celebrity endorsements including from actors Sylvester Stallone and Robert Duvall.

American TV superstar Oprah Winfrey might be backing Democratic presidential hopeful Barak Obama, but his rival Hillary Clinton got her own celebrity boost on Monday when Elton John announced he would perform a solo concert on behalf of her campaign on April 9 at Radio City Music Hall in New York.  The event, called “Elton and Hillary: One Night Only,” is the British star’s first public solo concert in New York City without his band in eight years. Ticket prices start at $125.

“I’m not a politician but I believe in the work that Hillary Clinton does,” said John.  “I’m excited to support Hillary by performing at what will be a truly memorable night.”

It’s a tight race between Obama, who would be the United States’ first black president if successful, and Clinton, who also would break new ground by being the first female president.