Will Wilkinson observes that "the point of the difference principle in Rawls" is to ensure that "the system benefits everyone, and not only those with the most power to ensure that it benefits them," since "a system of institutions requires that everyone living within it have reason to support it, and to comply with the terms of association it lays down, if it is to be well-ordered and stable."
Now this certainly sounds like something that Rawls might say. But in practice, it's not clear to me that it ends up differing very interestingly or importantly from my own, admittedly somewhat brassier and tackier, summary: in settling institutional arrangements, the interests of worse off groups trump the interests of better off groups. Notoriously, Rawls gerrymanders the original position in such a way that the parties behind the veil of ignorance can only proceed as if they were all going to end up among the worst off. So maximizing the minimum becomes the overriding goal.
Wilkinson suggests that he would not take things as far as Rawls does: instead of the interests of the worst off group acting as an absolute trump, perhaps they would merely count for some multiple greater than one compared to the interests of better off groups.
But the question remains, why should anybody in the real world who's not a member of the worst-off group of all buy into any of this to begin with? I mean, if you start off with a liberal moral sensibility - i.e., a moral sensibility that is deeply disturbed by the undeserved inequalities that the world deals out in such profusion - then sure: you'll find Rawls' project compelling. But if, like me, you don't - well, then, you won't.
And this hardly means adopting the viewpoint of Thrasymachus - that "justice is the will of the stronger." It just means caring more about your own life, and the lives of those close to you, than you care about far-away people whom you don't know from Adam. I.e., it means being a normal human being, as shaped by the evolutionary aeons.
As for "justice?" What is justice? I dunno. But it sure as heck ain't fairness.
Finally: Wilkinson mentions "fundamental rights to physical movement and voluntary association." And I'm sure he will have anticipated my reply: terrific - but not on my dime. Fact is, the "fundamental rights" of illegal immigrants to the U.S. are now held to include not only "physical movement and voluntary association," but also use of publicly funded roads, publicly funded healthcare, publicly funded schools, etc. - all adding up to much more than they pay in taxes. And he knows as well as I do that there's not a damn thing that anybody can do about it.
P.S.: The claim that a stable "system of institutions requires that everyone living within it have reason to support it" is a charming conceit, and, as I say, sounds like something that Rawls might say, but isn't it pretty obviously false? Aren't there slave-owning polities, for example, that survived for many more centuries than ours has, so far?
But perhaps they weren't well-ordered. Who can say?