Vouchers only provide a level playing field if any school that accepts vouchers takes those vouchers as full and complete payment with no strings attached - no required parental participation hours etc.  I do not want vouchers to subsidize the upper middle class and leave the poor behind.  So - vouchers must be taken as 100% payment if vouchers are accepted.  No exceptions.  You cannot add personal money to the value of a voucher.  I might support vouchers under those circumstances.