First, the ESAs aren't simply vouchers for private schools, where the state picks up the cost of private school tuition, or a portion of the cost. They're vouchers for every child who isn't enrolled in a publicly funded school, district or charter. As well as children attending private schools, it includes a wide variety of home schoolers. So long as the children aren't enrolled in publicly funded schools, parents can get accounts containing taxpayer money they can draw on for any approved educational cost. That includes private school tuition, of course, but it can also include textbooks, educational therapies or services, tutoring, tuition for a learning program, the cost of tests such as the SAT and so on. If parents want to be entirely responsible for their children's educations or if they want to create a cafeteria-style, pick-from-the-menu education strategy which includes tutoring, individual classes and so on, the ESA lets them do that, all on the taxpayer dime. If any money is left over at the end of the year—and many home schoolers would have lots of money left over—it can be rolled over year after year. Anything left at the end of K-12 can be used for college. The idea of subsidizing home schooling, and even encouraging home schooling by dangling the prospect of having money left over to pay for college, creates all kinds of frightening scenarios in which parents who aren't equipped educationally or emotionally to educate their kids will be lured into trying to provide education on the cheap by the prospect of subsidized college education.
Next, to qualify for an ESA, a child must spend at least 100 days at a publicly funded school. That's a little more than half of a 180 day school year. So, put your five year old in a public kindergarten, leave the child there for the whole year or just the first hundred days, and you get the next twelve years of non-public education paid for by the taxpayer.
But how much will the state pay for each child? That's a phenomenally important question. The answer is somewhere between $3,500 and $5,000 per year for most children, based on estimates I've read. Children who need educational assistance beyond the normal classroom—they have physical or mental handicaps, they qualify for ELL, etc.—get more money allotted to them, just as they do in all publicly funded schools. It can be upwards to $20,000 a year, and maybe more in some cases.
For now, let's just look at the majority of children who don't need any special assistance. Let's estimate their ESAs are $4,000 a year and see what that will buy on the private school market. It won't pay most private elementary school tuitions, and it won't come close to paying most private high school tuitions. You can find schools whose tuition is in that ballpark, but the institutions have to scrimp on staff and services unless they're heavily subsidized. Really, the only reason to send a child to one of those low tuition schools is to get a religious education. Over 70 percent of Arizona's private schools are religiously affiliated—the percentage is similar around the country—and the schools with rock bottom prices aren't known for providing a quality education in non-religious subjects.
If parents want to send their children to what most people would consider a quality private school, one they might expect to provide a better education than a district school or charter, they're probably going to have to kick in a substantial amount of tuition money on their own, then they'll have to pay for textbooks, general supplies and other "extras." That means the people who will benefit most from the ESA money are upper middle class or upper class parents who can already afford the schools or come close. And benefit they would! They'd get a $4,000 scholarship to the expensive private school of their choice, courtesy of the taxpayer. As a bonus, they wouldn't have to worry about their children rubbing elbows with the riff raff, even those with ESAs. Lower income kids couldn't afford the school even with a $4,000 ESA boost, and if they could figure out a way to scrape the money together, well, remember, private schools can pick and choose which students they enroll, so it wouldn't be hard to figure out ways to exclude members of the great unwashed even if they somehow had the money.
The people who will benefit most from ESAs are people who can already afford private school or are only a few thousand dollars short of affording it, which should be a surprise to no one who has even a nodding acquaintance with Republican priorities. All those upper income folks have to do is put their children in public school for a hundred days, and they're golden through high school graduation.