When he wrapped up a weeklong trip to Sudan's war-ravaged Darfur province with his journalist father, Nick, last month, George Clooney knew he couldn't turn his back on the countless victims of atrocities he'd met during his visit—a handful of the area's 2.5 million refugees. To help them, Clooney, who visited Darfur after reading reports about genocide there, turned his star power on Washington, D.C., where the actor lobbied for more U.S. aid to end violence by Arab militia groups (see box). At a National Press Club event April 27, Clooney joined Sens. Barack Obama (D-Ill.) and Sam Brownback (R-Kan.), sponsors of bipartisan legislation backing international peacekeeping forces in the area. "What we cannot do," he said, "is turn our heads and look away."
On April 29 Clooney partied with politicos, celebs and journalists at the White House Correspondents' Dinner. "I'm a little shell-shocked" by the attention, he told PEOPLE. "We've got the rally tomorrow, and I hope some people show up." They did. Some 75,000 gathered at the National Mall April 30, where Clooney, 45, demanded an end to what he termed "the first genocide of the 21st century." Still, he said he's hardly giving up. "There is hope," he told the cheering crowd. "[That hope is] all of you."