A student in an English class works on a project dressed in the uniform worn by all students at the Frederick Charter School. (AP Photo/The Frederick News-Post,Bill Green)

+ What is the most important thing the next administration could do to change disparities in K-12 education?

Andrew J. Rotherham is a co-founder of and partner at Bellwether Education, a national nonprofit educational consulting firm. He worked in the White House during the Clinton administration and has analyzed charter school policy for two decades.

You wouldn’t know it from how our politicians talk about school choice, but we actually know quite a bit about what works and what doesn’t. Broadly speaking, vouchers have at best a modest effect on student achievement but seem to improve certain other outcomes of interest, such as parental satisfaction and graduation rates. Charter schools, for their part, outperform on standardized tests in urban areas, show mixed but positive results elsewhere, and have pockets of serious underperformance. There is some evidence that choice helps spur the overall school system to improve, but not as much as free market adherents might think. In other words, the zealots on all sides are wrong: If you want to see a more equitable American education system, choice is a key ingredient but not by itself transformative.

Good luck finding that kind of nuance in this year’s presidential race. One candidate treats charter schools like a minefield while the other sees them as a club.

Hillary Clinton, caught between Democratic special interests and parents who want choice, has been calculatedly vague about her views on charter schooling. Her husband championed charters when they were a new idea in 1992, but now they educate millions of students, including the majority in several U.S. cities. That kind of growth has teachers unions and others eager to curtail — if not end — chartering, especially after eight years of a generally supportive Obama administration.

Donald Trump seems to care little about balancing various competing political interests. Instead, his problem is at the opposite extreme. To the extent he’s thought about school choice, it seems he’s never met an option he doesn’t support. That may sound refreshing, but it flies in the face of what we know about school choice: namely that program design matters and quality matters as much as quantity.

When the dust settles, the next administration must navigate between these poles. Charter schools can work and right now are changing students’ life trajectories, even if they’re out of fashion on the political left. The United States needs many more of them. But growing them responsibly is more complicated than just calling for “more.” The politics aren’t easy, but hopefully the next president can find a way to support an expansion of choice — in ways that reflect what experience has taught us and that promotes innovation around emerging challenges.

The Obama administration has helped support the replication of high-quality charter schools, a valuable federal role. But the next administration can do a lot more. It can help support pilot initiatives to incorporate more radical uses of technology and different labor models. That could include, for instance, the teacher-run charter schools emerging in Minnesota; schools such as the West Coast-based Summit Public Schools that flip the traditional notion of the role of student in school; or schools that are now still just an idea in an educator’s head somewhere. The next president can also pilot better strategies to ensure that the charter sector in a city or state serves an equitable share of students with special needs — an emerging problem as the charter sector grows. There are also subtler steps around data and accountability that would encourage better practices.

Yet given the limited reach of federal policy, perhaps the most important thing a president could do now is use the bully pulpit of the White House to make the case that while choice is not a panacea, good schools and education empowerment have been denied to low-income and working-class Americans for far too long — often by more affluent Americans who take these things for granted. That conversation is the political predicate for moving forward using the evidence about what works and what doesn’t when it comes to education.

The counterargument:

Michael J. Petrilli: To improve education, focus on excellence — not failure