Actor George Clooney stopped by the White House on Thursday to help bring attention to the plight of the people in south Sudan, a cause the Hollywood heavyweight has championed for years.

Clooney, who arrived back from a tour of that region two days ago, lobbied lawmakers on Capitol Hill and mingled at the White House’s state dinner Wednesday for British Prime Minister David Cameron.

Coming out after his briefing to talk with reporters, Clooney set off a bit of media scrum as the White House press corps jostled to get a spot near the stake-out microphone set up on the West Wing side of the North Lawn.

Clooney said he pressed the president to push China to help force the Sudanese government to open the southern region to relief efforts to help get food to large swaths of people, who otherwise could face potential starvation with the upcoming rainy season.

“What is most striking and most devastating is the absolute vulnerability of a certain group of people,” Clooney said. John Prendergast, co-founder of the Enough Project, a human rights project, accompanied Clooney.

Clooney said Obama promised to push Chinese President Hu Jintao on the issue at an upcoming bilateral meeting. Asked whether he’s had difficulty raising money for the cause, Clooney replied: “No question there’s donor fatigue. There is misery fatigue. People turn on the news and see an awful lot of bad stories. ... On the other hand, having traveled the world and tried to raise money in other parts of the world, this is still the most generous country in the world and truly the most compassionate.”

The actor said he has not yet seen the Kony2012 video that has gone viral on YouTube in an attempt to bring attention to Ugandan warlord Joseph Kony’s abuse of children. Clooney, who was in Sudan when the video gained fame, is seen in a clip and he said he supports the effort.

But he couldn’t escape a more pressing political question at 1600 Pennsylvania Avenue.

Asked about Obama’s chances for re-election, Clooney, who has donated money to his campaign, said: “I hope they’re very good. I’m a Democrat and a supporter of the president. I hope he has a successful election.”