President Obama said Wednesday that disquiet and a sense of frustration in the country are fueling cynicism about government that could hurt Democratic turnout in the November elections.

Obama told high-dollar contributors at the Los Angeles home of Disney Studios Chairman Alan Horn that he feels a sense of urgency about the election and needs the Senate to remain Democratic. Republicans have a chance to win control of the Senate this year.

Obama spoke before about 90 contributors who paid from $10,000 to $32,400 to attend. Among those attending were Hollywood luminaries Barbra Streisand, James Brolin and Jeffrey Katzenberg.

Obama said the political system faces challenges from legislative procedures, a partisan media and too much money in politics. But he said the main cause for gridlock was fundamental differences between what Democrats believe and "what this particular brand of Republicans in Congress believes."

He said the gridlock in government has disillusioned many of the voters upon whom Democrats rely.

"When they get discouraged they don't vote," he said. "We have to break out of that cycle, and that is what this election is about."

Obama emphasized the need to retain a Democratic majority in the Senate. With House Minority Leader Nancy Pelosi in the audience, he also called for Democrats to make a push to recapture control of the House, though many party activists have little hope of achieving that.

Obama was holding five fundraisers for the Democratic Party during a three-day California swing. Later Wednesday, he spoke at 20th anniversary of Steven Spielberg's USC Shoah Foundation, offering a staunch defense of Israel.

"It's up to us to speak out against rhetoric that threatens the existence of a Jewish homeland and to sustain America's unshakable commitment to Israel's security," Obama said in his speech saluting the Holocaust history foundation.

Spielberg established the foundation 20 years ago to collect video testimonies from survivors of the Holocaust and other genocides. The video archive now includes more than 50,000 personal accounts and is available to schools across the globe. 

Obama said the devastation in Syria, murders and kidnappings in Nigeria, and tribal conflicts elsewhere in the world underscore that decades after the Holocaust, "we have not yet extinguished man's darkest impulses." 

Obama received the foundation's Ambassador for Humanity Award at a gala event that featured a performance by Bruce Springsteen.

The Associated Press contributed to this report.