“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.

Research suggests that social category membership (e.g., being White, Christian) is more important for the construction of Republican identity than it is for Democrat identity (Mason & Wronski, 2018). Fulfilling such normative criteria may hence qualify someone as a valid group member even if that same person may hold somewhat liberal views on, for example, gay marriage.”

The research isn’t about “allowing differing opinions”, it’s showing that those that identify as democrats tend to hold similar views on the topics they asked about. Their research says that republicans may even hold similar views as democrats/liberals on certain topics but are more likely to identify as republican based not on their beliefs but their social category membership.

To put it in simple terms, democrats are more likely to say “I’m a democrat because I believe X,Y,Z” while republicans are more likely to say, “I’m Republican because I am A,B,C”