Over the past two years, school voucher systems and other related schemes that divert taxpayer revenue toward private K-12 tuition have passed state legislatures at unprecedented rates. Although these recent bills became law only, for the most part, in red states, their supporters include a handful of Democrats in other parts of the country as well. And all of this comes despite a decade of evidence that vouchers have led to some of the steepest declines in student achievement on record.