Family Research Council praised the decision by the U.S. Supreme Court in Espinoza vs. Montana, which held that it is a violation of the First Amendment to discriminate against religious activity by disallowing neutral and generally-available student-aid programs simply because they afford students the choice of attending religious schools.
Delivering the court's opinion, US Supreme Court Chief Justice John Roberts wrote: "A State need not subsidize private education".
The high court also is weighing a Trump administration policy that would make it easier for employers to claim a religious or moral exemption and avoid paying for contraceptives for women covered by their health plans.
Education Secretary Betsy DeVos, long a champion of school vouchers, was on hand for oral arguments before the High Court in January. Christian conservatives are an important voter bloc for Trump, who is seeking re-election on November 3. Ted Cruz (R., Texas) have proposed a $5 billion tax credit to support private education, through which participating states provide dollar-for-dollar credits to taxpayers who contribute to scholarship programs. "But once a state decides to do so, it can not disqualify some private schools exclusively because they are religious", Roberts said.
In a concurring opinion, Thomas said the Supreme Court still needs to address its interpretation of the First Amendment clause prohibiting government establishment of religion, because it "continues to hamper free exercise rights".
Thirty-eight states have constitutional provisions like Montana's barring public aid to religious entities. Breyer said the ruling could lead to legal fights over whether states have to directly fund religious schools as well as secular public schools.
"This is a landmark case in education that will allow states across the country to enact educational choice programs that give parents maximum educational options", Smith said.
The National Education Association, a union representing public school teachers, said the ruling could undermine public schools because vital education funding could be siphoned to religious schools.
"The majority's approach and its conclusion in this case, I fear, risk the kind of entanglement and conflict that the religion clauses are meant to prevent", Breyer wrote in a dissent partly joined by Justice Elena Kagan.
The state supreme court overruled that decision and ordered the entire program to be scrapped.
The Montana tax credit program, created in 2015, provided up to $150 as an incentive for donations to groups that fund scholarships for tuition to private schools including religious schools. The program approved by the state legislature includes Christian and other religious schools.
Rachel Laser, president of Americans United for Separation of Church and State, contended that numerous religious schools participating in Montana's program had discriminatory policies. Several attempts to provide tax credits for scholarship programs have failed amidst constitutional questions.
Three mothers whose children attended a private Christian school had sued after the Montana Department of Revenue issued a rule banning families from using the scholarships at religious schools.