Add some more star wattage to the Democratic National Convention this week. Oscar winner Jennifer Hudson has been asked to sing the national anthem on Thursday, when Barack Obama will give his address as the official Democratic candidate for president. "She's thrilled and excited," Jennifer's rep told E! Online. "It's a tremendous honor." Other A-listers who are in Denver this week are Oprah, George Clooney, Jennifer Lopez, Ben Affleck, Charlize Theron, Kanye West and Sheryl Crow. Bruce "The Boss" Springsteen will be closing the convention on Thursday night.