The enterprise of fact-checking continues to proliferate throughout the U.S. news media to an unprecedented degree. While many welcome this trend, others question the effectiveness of fact-checking and some have even begun to push back. A common critique is that fact- checking has failed to eradicate deceptive and misleading claims by politicians and is therefore ineffective. Others have concerns about the presence of bias in fact-checking work. This report draws on evidence from social science as well as recent interviews with reporters, fact-checkers, critics, and political figures to consider these issues and how they played out during the 2012 campaign. Because fact-checking is relatively young, robust metrics to empirically measure its effectiveness are still being established. Hence, a recurring theme in this report is the difficulty in definitively distinguishing the effects of fact-checking.