"Religious schools" refer to educational institutions that are affiliated with a specific religion or faith. These schools provide instruction based on religious beliefs and values, in addition to regular academic subjects. Full definition
The free speech clause might not seem relevant at first, but it too could be read to require the inclusion of religious schools in voucher programs. (educationnext.org)
The resulting vouchers are then used primarily for private religious schools that do not have to meet any of the standards required by the state of public schools. (fundeducationnow.org)