Vouchers may offer answers for some children. The Constitution should not be read to forbid policymakers from finding out. In fact, our quarrel with the Cleveland program would be that the vouchers are too small. Imagine how much competition might be generated, and with what respect poor parents might be treated, if they were given an $8,000 voucher for each child, and public schools really had to prove they were worth what society now spends on them.
G.W. Bush continues to support vouchers. Others prefer to say they are in favor of school choice instead. Despite voucher election losses in California in Michigan, this issue isn't going away.
Update: Good NY Times op-ed on vouchers by Milton Friedman.