Rasmus Skytte has an article at The British Journal of Political Science titled “Dimensions of Elite Partisan Polarization: Disentangling the Effects of Incivility and Issue Polarization.”
Elite partisan polarization has been found to have several potentially problematic effects on citizens, such as creating political distrust and different types of polarization among partisans. However, it remains unclear whether these effects are caused by the parties moving apart in terms of issue positions (issue polarization) or by the rise of disrespectful rhetoric (incivility). In the literature, these two dimensions of elite polarization often appear to affect citizens in similar ways, but typical research designs have not been well suited to disentangling their effects. To determine their unique effects, four studies have been conducted using original designs and a mix of experimental and observational data. The results show that issue polarization and incivility have clearly distinct effects. A more uncivil tone lowers political trust, but increasing issue polarization does not. Conversely, only issue polarization creates attitude polarization among partisans. Both aspects of elite polarization create affective polarization.