On p. 59, Cohen seems to show a misunderstanding of Rawls.
He posits a conflict between the talented, such as “highly paid managers and professionals” and “poorly paid workers, unemployed people, and people indigent for various personal and situational reasons, who depend on state welfare.”
This is wrong. Rawls, in constructing his argument, was concerned with distribution of goods between the cooperators within society, not between producers and full-time parasites, like the welfarites, old geezers living off Social Security taxes, or indeed the unemployed.
Rawls simply ignores the underclass or those who for whatever reason cannot engage in social cooperation, wisely considering the problems of crime and charitable giving to be beyond the scope of his book. His “worst off” are not bums on government dole; they are full-fledged producers who happen to be relatively but not completely deprived of gifts of nature or nurture (perhaps as children). We might even say that each of the Rawlsian wraiths behind the veil of ignorance expects to be incarnated as someone working 40 hour per week, though without knowing what his productivity will come to be.
It may be that egalitarianism demands that even those who do not produce at all be allocated an equal share of the communal income. But this would be an argument of Cohen’s own design. Rawls’ theory does not involve people who think they might upon exiting the veil of ignorance insist on being paid for doing nothing.
It is true that the completely disabled are part of any civilized society. There is a danger that a party in the original position will be instantiated as one of them. Moreover, such a person may not be a producer but would be if he could; he is not a hobo living off alms by choice. Nevertheless, considering them to be the worst-off would undermine Rawls’ system. The difference principle would be rendered nugatory, since the welfare of the completely disabled is always near zero. Their very survival is perpetually imperiled. They cannot be helped by inequalities or in any other Rawlsian way. If they are supported by charity (rather than by own family), then presumably just enough to barely subsist; so, even general economic progress will not improve their standard of living.
Perhaps Cohen would argue in favor of “from each, according to his ability; to each equally.” Everyone shall work for the welfare of the community with great fervor, motivated by the Cohenian egalitarian ethos, though be paid identically with everyone else. If one declares that his ability is zero, then he, too, will receive his proper equal share. He will not be denied citizenship in the commune. Once again this would be entirely Cohen’s own development that has nothing to do with Rawls.