One of the most comprehensive studies done to date, by Georgia State University, found that a sample of below-average pre-schoolers enrolled in Georgia’s universal pre-K program made up their deficits and were average or above average on most measurements by the end of kindergarten two years later. But the racial gap between white and black students actually became more pronounced after pre-K and kindergarten. Whether a student “lived with both parents continuously since birth” made a huge difference in achievement.

It’s only logical that little kids with such barren educational backgrounds that they can’t even do kindergarten work—mostly just coloring, identifying letters and shapes, and exhibiting a healthy vocabulary—will swiftly gain at least basic cognitive and social skills once they finally get the chance to soak them up. It doesn’t follow, however, that a year of pre-school can make up for the next 12 years of poor education and poor family support. A few longer-term studies exist, but they’re often too small to be useful, or suffer from methodological problems.

Worse, for the government to follow the science of cognitive development to its logical conclusion, the feds would need to mandate that local schools force single, poor mothers to enroll their kids at birth in government-funded, full-day education programs, staffed by highly trained professionals. This would ensure that the kids are away from their dysfunctional families and neighborhoods and in a comparatively decent learning environment for as much time as possible.

Thankfully, this idea still sounds ridiculous to most people—though maybe less so every year. And there’s no guarantee that it would work anyway, if the hundreds of billions of dollars spent on anti-poverty programs over the past 40 years are any indication.

Clinton’s plan is an equally absurd half-measure, assuming, as it does, that even more billions in state and federal taxpayer money—much of it funneled through teachers’ unions into schools that already do a crummy job of educating disadvantaged kids ages five through 18—can bridge immense familial and cultural chasms if they just start at age four instead.

This article originally appeared in The City Journal.