The school voucher movement seems to come and go out here. Luckily at the moment it is in deep cover since the public system will most likely get its first serious and positive attention in about thirty years.
For those struggling against it, I would suggest the voucher system be excoriated in the most brutal terms possible. Call it what it is: pure racist, capitalist pig, rightwing relligious fanaticism. Do you want your tax dollars spent to brainwash children? Forget compromise. This is nothing more than a piece of a piecemeal privatization plan that wants to turn all tax supported public institutions into schemes for profit.
For those states that already have a voucher system, I would start in a series of law suits to force the private schools to provide both facililites and programatic access to disabled children who are otherwise qualified and wish to use the voucher system. This is a little Machiavellian in that the point would be to break the voucher system by removing its profits, by requiring them to duplicate the mandated accessibility standards that public institutions are required to fulfill. It would take some very commited disabled kids and their parent to pull this off--but they are out there--it would be a matter of mobilizing them and supporting them in such a fight. Consider it something like a Brown v. Board of Ed on wheels.
It's hard to think of a rightwing attack on public institutions that I hate more than the voucher system.