Barack Obama in bed -- with Tyra Banks?! Not quite. The supermodel and a Barack look-alike donned Harvard sweatshirts -- the Illinois senator's Law School alma mater -- and posed under the covers for an upcoming issue of Harper's Bazaar. The fierce fashionista and talk hostess had a laugh with Obama on her show -- and admitted to Bazaar that she broke down in tears when it appeared he had nabbed the Democratic nomination. "If Barack Obama wins, kids are going to say that a black man can be president too," said the "America's Next Top Model" host. The pix -- also snapped in the "Oval office" -- paid homage to a famous JFK and Jackie spread. ...