SAN FRANCISCO—A new poll released today in California finds political momentum shifting dramatically toward Barack Obama—and away from both Hillary Clinton and John McCain—in the nation's most populous state. According to a survey conducted over the past 10 days by the Public Policy Institute of California, 59 percent of likely voters here now have a "favorable" impression of Democrat Obama, while a majority view both of the other candidates unfavorably. In a state whose Democratic primary Clinton won in February, 51 percent of voters now say they have an unfavorable opinion of her; 53 percent of voters feel the same way about Republican McCain.

Obama, meanwhile, seems to be making strides across nearly every constituency. If the general election were held today, 54 percent of Californians say they would vote for him, compared with 37 percent for McCain. That gap has widened by 8 points since March. Obama enjoys the support of more than 80 percent of Democrats here, along with over half (55 percent) of independents. He leads McCain among men and women and is viewed favorably by nearly 70 percent of Latinos—a powerful political group, experts note, not just in California but in several other western states, including Colorado, New Mexico, and Nevada.

While there has been an epidemic of hand-wringing among Democratic political analysts over Obama's inability to win over low-income white voters in states like Kentucky and West Virginia, where Clinton has dominated recent primaries, California seems to be a different story. Obama leads McCain by a double-digit margin here among likely voters, no matter what their incomes. He enjoys a 55-to-35 percent lead among those who make less than $40,000 a year, including whites; a 55-to-36 percent lead among those who make between $40,000 and $80,000; and a 53-to-37 percent lead among those who make $80,000 or more.

"As the presidential campaign has moved further away from California, what's been taking place is solid support among Democrats and increasing support among independent voters," says Mark Baldassare, president of the Public Policy Institute of California, the nonpartisan group that released the poll, which surveyed more than 2,000 voters. "John McCain is certainly going to have his work cut out for him here."