"Our first set of findings suggests that attitudes, emotions, and symbolic self-descriptions are interconnected elements which together define the meaning and the experience of partisan-based group identity. Such a holistic view on partisanship challenges interpretations of polarization as a largely emotional phenomenon (c.f., Iyengar et al., 2012). The results also show that the embedding of attitude positions into partisan identities is highly asymmetrical and thus more complex than bivariate polarization models would predict. Not only does the presented data suggest that Democrats embrace more extreme viewpoints on the selected issues compared with Republicans, but also that the Republican cluster includes some surprising issue positions that (under interval assumptions) might be assumed to fall into the Democrat cluster (c.f., Figure 2a). "

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"According to the present findings, Democrats (more than Republicans) tightly centre their belief-system around a set of positions at the extremes of these particular items, implying that people who deviate from these positions are likely to be considered as outgroup members (extremity should thereby be understood as a function of both, the formulation of the item and the response). It is possible that holding extreme (and thus unnegotiable) attitudes on important social-political issues has become increasingly identity defining for Democrats, not least in response to Donald Trump's controversial presidency. The pattern does not imply that Republicans are more tolerant than Democrats, nor that Republicans could deal better with attitudinal uncertainty. It does imply, however, that –at this particular moment in time– Democrats and Republicans are constructing and managing their partisan identities differently in relation to the topics reflected in these questionnaire items. "

https://bpspsychub.onlinelibrary.wiley.com/doi/10.1111/bjso.12665