Arianna Huffington — yes that Arianna Huffington — wrote an interesting article this week reiterating her support for private school choice.

I’d just like to say thanks for opening fire from the left on this issue. Unfortunately, Arianna supports a federal, single-payer voucher system, and there are a few problems with that approach.

Let’s start with feasibility. Vouchers are controversial at the state level, and they would be even more so at the federal level. Current funding is mostly through state and local taxes, so — as Huffington notes — a new federal tax would be required. A federal voucher program is, thankfully, extremely improbable.

In fact, even state-level vouchers are less preferable than education tax credits.

Education tax credits are less controversial and more popular than vouchers. A recent poll from Education Next found an astonishing 57 percent of public school teachers support tax credits. Only 26 percent support vouchers.

Numerous voucher programs have been overturned for violating state constitutions; no tax credit programs have been overturned. That’s because credits allow individual taxpayers to keep control of their money, rather than sending it to the government to dole out. In other words, no taxpayer is compelled to support education with which she disagrees.

Tax credits are also a more cost-effective way to fund private choice. For instance, instead of instituting de facto government price controls with a single voucher amount, private scholarship organizations can provide only what a family needs to attend a school of choice. Existing tax credit programs support many more families with each dollar than voucher programs.

So, Arianna, you see the necessity for private school choice. Why not make your next article about the promise of state education tax credits?