And he warned that if government doesn't address such issues as global warming, the federal deficit and lack of investment in education, "We may be consigning the next generation to an America that is a little meaner and a little poorer than the one we inherited.
"That is un-American," he told a crowd of about 1,000 people gathered in San Francisco for a fundraiser for U.S. Senator Barbara Boxer.
The audience saved its biggest applause for Obama's blunt assessment of the war in Iraq.
"We're in the midst of a war that should have never been authorized," he said. "As a consequence of our misguided policies in Iraq, we find ourselves less safe."
Obama had agreed to appear at the Boxer fundraiser last year, before he announced his bid to become the Democratic nominee. He planned to end his evening at a party in Portola Valley, where more than 200 people many of whom had already given the maximum
$2,300 contribution to Obama's campaign were expected.
Earlier in the evening, a glowing Boxer announced to reporters she will run for re-election in 2010. She added that she expected to raise $350,000 from the Obama event.
Both Obama and Boxer are vocal opponents of the war in Iraq.
Obama introduced a bill in the Senate last month imposing a phased "redeployment of U.S. forces with the goal of removing all combat brigades" from Iraq by March 31, 2008.
Since his much-anticipated announcement 10 days ago that he would seek the presidency, Obama has been making a cross-country tour, combining fundraising for his own bid with carefully staged public events.
Between Sunday and today, he will have held more than half a dozen fundraisers in San Diego, San Francisco and the Los Angeles area, including a star-studded event in Beverly Hills tonight. His only public event in California is a rally in Los Angeles today.
Obama spent much of Monday in the Bay Area meeting privately with supporters.
and at a fundraising luncheon for his own campaign at a San Francisco law firm, in addition to Boxer's event at the Westin St. Francis Hotel.
With intense media interest in Obama, Boxer used the opportunity to formally announce in front of more than a dozen reporters that she is running for a fourth Senate term. Gov. Arnold Schwarzenegger has been mentioned as a possible Republican rival for her seat.
Boxer acknowledged she is starting to raise money two years earlier than she did for her 2004 election. "I'm not sending anybody a message," she laughed. "I will tell you we're going to have a tough race. We always have a tough race."
She intends to remain neutral in the race for the 2008 Democratic presidential nominee because several of those running or expected to make a bid are Senate colleagues including her close ally and friend, Hillary Clinton. Boxer's daughter was formerly married to Clinton's brother.
"We have a lot of star power in the race," Boxer said. "And Barack is certainly one of them."
Among Obama's list of Bay Area supporters are San Francisco district attorney Kamala Harris, Hummer Winblad venture capitalist Mark Gorenberg and John Roos, chief executive officer of technology law firm Wilson Sonsini Goodrich & Rosati in Palo Alto.
The Bay Area is seeing a parade of potential presidents this month. Among those giving speeches, raising money and meeting with supporters last week were former New York Mayor Rudy Giuliani, a Republican; 2004 Democratic vice presidential nominee John Edwards; and former Iowa Gov. Tom Vilsack, a Democrat. Former New Mexico Gov. Bill Richardson, a Democrat, is meeting with supporters in San Francisco and Palo Alto today. Democratic U.S. Sen. Hillary Clinton arrives late in the week for a private visit to Google and a major San Francisco fundraiser on Friday.
The area's early barrage of attention has several causes: the strong likelihood California will move its primary up to next February, excitement generated by high-profile candidates such as Giuliani, Obama and Clinton and a wide-open race on both the Democratic and Republican sides.
The 2008 campaign is the first in 80 years in which neither a sitting president nor vice president is seeking the presidency.