The basic idea behind the public reason project:

To justify imposing some norm, law, policy, or rule P on reasonable people, you need to show that they have sufficient reason to endorse P by their own lights, given what they believe and what they care about.

Public reason theorists do not think actual consent is necessary for coercive government policies. But they also deny that “The correct theory of justice says we should do P” is good enough. They want something in between.

But they face a number of problems, including how to deal with real-life citizens, who are often quite unreasonable (according to their theory of what counts as “reasonable”), who might lack any potential to converge on or have consensus on policies, and so on.

So, every theory ends up “idealizing” citizens to a certain degree. But this runs into a serious problem, as Jonathan Quong summarizes here:

On the one hand, if the degree of idealization is kept to a minimum, then public reason may result in anarchy, or may fail to deliver minimally acceptable results; for example, rules prohibiting discrimination on the basis of race or sex may not be justifiable to only modestly idealized parties. On the other hand, if the degree of idealization is very substantial, this creates two different worries. First, it’s no longer clear in what sense the resulting rules are justifiable to the real persons bound by the rules. The whole apparatus of public justification might seem superfluous (Van Schoelandt 2015); it would be simpler and more accurate to simply present certain principles or reasons as true, and declare that anyone who refuses to acknowledge their truth is making an error. Second, and relatedly, too much idealization may implausibly entail that almost all real persons are excluded from the constituency of public reason (Enoch 2015, 122–23).

Public reason liberals often end up saying that people would have reason to accept certain principles or policies if only those people were, well, different from how they are. Further, the more one idealizes, the more one seems to be saying that people would have reason to accept those principles or policies because they are, well, true. In addition, idealization seems to mean we are not publically justifying principles and policies to the actual public subject to those policies, but to a hypothetical public. To that degree, the public reason project fails on its own terms; it means that we are imposing rules and policies on the actual people subject to such policies without justifying those rules or policies by their own lights.

I’ve been reading public reason work somewhat widely over the past few weeks, and I don’t see how PRLs get away from Enoch’s and van Schoelandt’s criticisms. Even Gaus, who goes for very mild idealization, seems to defend a theory which involves shoving policies down most people’s throats without justifying such policies in ways that respond to the reasons those citizens really have.