Quarter-baked idea: It seems to me that it might be fruitful to try to marry post-liberalism with a modified Rawlsian contractarianism. This might solve a problem with Rawls’ project and a problem with the post-liberal project.
As Rawls says at one point, “the idea is to derive satisfactory principles from the weakest possible assumptions. The premises of the theory should be simple and reasonable conditions that everyone or most everyone would grant, and for which convincing philosophical arguments can be given” (A Theory of Justice, rev. ed., 456–457).
The problem is that no such common ground necessarily exists — the assumptions are too weak. Some worldviews, including, I would argue, the Christian worldview, are shorn of relevant considerations in the original position. (I think something similar could be said about an Islamic worldview or certain CRT tenets which function as a worldview and maybe some forms of Judaism.) Consequently, the original position ends up skewing our moral compass. This seems like an inherent liability to the original position on any sufficiently robust natural law theory.*
Rawls might anticipate this objection on page 454: “the resulting balance of justice, made possible by the greater consensus, outweighs what may have been lost by ignoring certain potentially relevant aspects of moral situations.”
Attempting to show this isn’t true and that his “balance of justice” is unstable would involve too detailed an argument than I want to dive into here — addressing the section in which Rawls attempts to lay out the opposite and his three “laws” of psychology. Suffice it to say that his claim on page 454 is left mainly as an assertion and one that doesn’t have prima facie validity for certain conservative views (and I would imagine certain liberal views too?).
But if Rawls’ assumptions in the original position are too weak, then this is where a post-liberal might make the case for a more robust understanding of the common good. That might solve a problem with Rawls project. And, by adopting Rawls’ framework, the rest of his project could provide a roadmap for spelling out the details of a post-liberal society — thereby answering one of the most common objections to post-liberalism.
* Rawls says at one point that his view can be seen as a sort of natural law theory.