PARTY POLARIZATION, MEDIA CHOICE, AND MASS PARTISAN-IDEOLOGICAL SORTING.

What is the relationship between party polarization, media fragmentation, and partisan-ideological sorting? The growth and availability of partisan media--afforded through the expansion of cable, satellite, and Internet penetration--is often linked to the consistency and extremity of individuals' political attitudes and partisan identities. At the same time, the literature on mass audiences and media choice suggests that the effects of choice and partisan media should be differential according to levels of political interest. This debate has yet to fully articulate a role for elite party polarization, which has been identified as a primary cue to facilitate mass partisanship and sorting. Synthesizing these bodies of scholarship, we utilize a variety of data to assess the influence of elite polarization, media fragmentation, and political interest on partisan- ideological sorting. We find that sorting is consistently connected to perceptions of polarization and qualified evidence that media fragmentation is related to partisan-ideological sorting. The expansion of cable and satellite programming is positively related to sorting, but this effect is isolated to individuals highly interested in news and politics. [ABSTRACT FROM AUTHOR]