When President Obama nominated former Harvard President Larry Summers to replace Ben Bernanke as the chairman of the Federal Reserve, it was a controversial move. And, now that Summers is facing opposition from the left, he's decided to withdraw the nomination. "I have reluctantly concluded that any possible confirmation process for me would be acrimonious and would not serve the interest of the Federal Reserve, the Administration or, ultimately, the interests of the nation's ongoing economic recovery," Summers wrote to Obama. More than 200 economists have signed an open letter urging Obama to nominate current Fed Vice Chair Janet Yellen. Obama released a statement saying he accepted the withdrawl and praising Summers for his "tireless work and service on behalf of his country."