A pair of Gizmodo stories have prompted journalists to ask questions about Facebook’s power to manipulate political opinion in an already heated election year. If the claims are accurate, Facebook contractors have depressed some conservative news, and their curatorial hand affects the Facebook Trending list more than the public realizes. Mark Zuckerberg took to his Facebook page yesterday to argue that Facebook does everything possible to be neutral and that there are significant procedures in place to minimize biased coverage. He also promises to look into the accusations.