Gov. Doug Ducey last week signed into law an expansion of the state’s Empowerment Scholarship Account, or ESA, program — they’re basically school vouchers.

The new law will make pretty much all students eligible for ESAs but will keep the current cap on the total number who can use them for a few more years, although supporters are already talking about ultimately removing that cap altogether.

With me to talk about ESA and other voucher programs across the country is Marty West. He’s an associate professor of education at the Harvard Graduate School of Education.