I agree with Rick that "the case for educational choice [is] not only about competition, and not only about assisting the poor, but also about religious freedom and value-pluralism." But I think that religious freedom and value pluralism also support skewing funding for school choice toward low- and modest-income families, or at least away from high-income families. After all, the real-world argument for vouchers is, as Rick put it earlier, that the wealthy already are "able to exercise 'choice'" -- that is, to pursue their religious and other values through education -- "by . . . paying for private schools," while low- and modest-income families "cannot afford [such] alternatives." If voucher amounts are limited, modest-income families will have only limited choices among private schools -- and given limited available funding, every voucher dollar given to a high-income family is one less voucher dollar to make the religious and value choices of modest-income families possible in practice. Put differently, all families have a right to religious freedom and educational choice, but some families have much more need than others of government assistance to pursue that right in practice, and prudent allocation of limited funds will take account of that fact. So my inclination is to have the per-student voucher graduated according to income (as Utah's proposal did) and eliminate it above a certain income level (which Utah's proposal did not).
I don't know if Rick and I disagree in principle on this, since his argument is for providing assistance not to high-income families, but to "families who are not, strictly speaking, 'poor,' and whose public schools are not awful, and who would prefer to form their children (as is their duty) through an education that integrates faith into the process." I agree that the interest in choice extends beyond families in failing public-school systems, and extends also to middle-class families who otherwise would find it hard to pay for choices in education. Rick, would you in turn agree that even the interests in "religious freedom and value-pluralism" can support graduating the voucher amount by income (perhaps cutting it off above a certain level)?
Tom