With its recent adoption of a tax credit scholarship program, Illinois became the 18th state to adopt an innocuously named — but highly controversial — policy that critics have described as a "backdoor voucher."
In some sense, the description is apt. But by injecting a middle layer into the government's support of private school tuition, tax credits help avoid some of the legal and political obstacles that have dogged efforts by advocates, like Education Secretary Betsy DeVos, to promote school choice through vouchers.
Perhaps as a result, more students now use tax incentive programs than vouchers to attend private schools in the U.S. A federal tax credit is also seen as the Trump administration's favored approach for promoting school choice at the federal level, though its immediate progress looks increasingly unlikely.