PREZ CANDIDATES GIVING BACK TO GAIN VOTES? MCCAIN, CLINTON, OBAMA TO BE ON 'IDOL GIVES BACK' By JARETT WIESELMAN Obama, Clinton and McCain will all appear on 'Idol Gives Back,' but no word yet if they'll actually sing. April 8, 2008 -- For the first time in any of their respective campaigns, presidential hopefuls Hillary Clinton, Barack Obama and John McCain are all uniting for one cause: "American Idol." The three wanna-be Commander-in-Chiefs will each make an appearance on tomorrow night's "Idol Gives Back" special that aims to raise funds to benefit various U.S. and international charities. Embracing pop culture trends in an attempt to amass additional votes is nothing new to this group of candidates: McCain has used the endorsement of "The Hills" star Heidi Montag as a way of seeming more in touch with the nation's youth while Obama has shaken his booty on "The Ellen DeGeneres Show" and Clinton lampooned herself on "Saturday Night Live." The three Senators will be joined by a cavalcade of celebrities who are all aiming to surpass the $76 million that was raised by the Emmy Award winning special last year. Miley Cyrus performs her hit song "Broken Chains" while "American Idol" winner Carrie Underwood covers George Michael's "Praying for Time." But arguably the biggest star lending his wattage to the event is Brad Pitt whose sheer presence caused such an uproar in the studio, filming had to be halted while the crowd calmed down. In fact, the guest list for "Idol Gives Back" (airing Wednesday, April 9 7:30-10:00 PM ET/PT on FOX) reads like a who's who of Hollywood. Also making appearances on the special are Victoria and David Beckham, Jim Carrey, Adam Sandler, Alicia Keys, Reese Witherspoon, Julianne Moore, The Jonas Brothers, Felicity Huffman, Toby Keith, Whoopi Goldberg, Amy Adams, Bono, Celine Dion, Eli and Peyton Manning, Fergie, Forest Whitaker, Jennifer Connolly, John Legend, Mariah Carey and Robin Williams.