I suppose I should jump into the fray, as I have some thoughts on the ongoing debate between Jason and Kevin on public reason.
Let's take as our starting point the observation that people will inevitably disagree about the right thing to do about abortion, immigration, capital punishment, and so on. Moreover, simply insisting on getting our own way all the time is a recipe for endless conflict. Thus, we might want to figure out how to live our lives together despite our moral disagreements. In this spirit, Kevin analogizes the public reason liberal to a marriage counselor--the point is arrive at a compromise that the spouses can live with even if neither gets exactly what they want.
But the marriage counseling case is disanalogous to the moral case in a critical respect, at least if you believe that there is a stance-independent fact of the
matter about various moral problems. If so, a better analogy would be a disagreement about, say, what a 20% tip on a restaurant bill is. Here, there's a right answer. Of course, a marriage counselor might still tell you to split the difference between your two answers and get on with your lives for the sake of marital harmony. Fair enough. But we might also care a lot about figuring out the correct answer. Indeed, if you're a mathematician, it seems like that is precisely what you would care most about. Similarly, if you're a political philosopher, it seems like you might care most about figuring out the truth about justice.
Of course, this is not to deny that figuring out how to live together in the midst of disagreement is important. But, as Jason notes, lots of theorists think this is important. Welfarist consequentialists, for example, will argue that peace and stability are worthwhile because they promote welfare. Virtue ethicists might argue that pushing people around is vicious. Kantians might argue that steamrolling others violates deontic side constraints. One need not be a public reason liberal to care about resolving conflicts in mutually acceptable ways.