NEW YORK (AP) - Barack Obama revealed Wednesday that former President Clinton, once the presidential nominee's nemesis, will campaign for him during the weeks leading up to Election Day. "There's nobody smarter in politics," Obama said on CBS' "Late Show with David Letterman," scheduled to air Wednesday night. "And he is going to be campaigning for us over the next eight weeks, which I'm thrilled by." The two were scheduled to have lunch Thursday at Clinton's office in New York. Clinton spokesman Matt McKenna said the former president would campaign for Obama at a yet-to-be announced site in Florida on...