The chapters in this book suggest that scholars are nowhere near a consensus on whether the mass public is more polarized than it has been in the past and, if it is, relative to precisely when. Nonetheless, among those who believe the mass public has, indeed, become increasingly polarized in its views, mass media are very likely to be invoked as a cause. Perhaps this should come as no surprise - throughout American history, mass media have been blamed for just about every social ill that has befallen the country. But in the midst of so much disagreement about when and whether and among whom this phenomenon has occurred, why is there so much agreement that media must somehow be to blame? A consensus on this point exists not so much because the empirical evidence is overwhelming, but because there are multiple theories that predict and explain how media might logically influence levels of mass polarization. Furthermore, it is possible to view mass media as engines of polarization even if one believes the public in general has not become polarized to any significant degree. Mass media are, after all, only one influence in a much larger system of institutions and influences. For purposes of this chapter, I set aside the question of whether and to what extent mass polarization has occurred, in favor of an exploration of ways in which media have been implicated in polarizing processes. How might mass media be contributing to this widely decried state of affairs? And even if the public has not polarized, how might mass media nonetheless be encouraging mass opinion in more extreme directions?