Twenty years ago today, the first public charter school, City Academy High School, opened in St. Paul, Minn. Now, more than two million -- or 4.2 percent of -- students in 41 states and D.C. attend a charter school, with some 610,000 more occupying spots on waiting lists.

Charter schools are publicly funded, but can be privately run. They're often based around the idea of a promise: people who want to create these types of schools can get more flexibility to do things like experiment with curriculum, personnel, even the structure of a school, in exchange for producing results aligned with a charter document that outlines a school's mission and goals. Additionally, charter school teachers don't have to be union members, which gives administrators more leeway over who they can hire, how to pay them and how to judge their teaching.

Over the last 10 years, Americans have expressed increased support for charter schools, peaking last year with 70 percent in favor, according to Phi Delta Kappa/Gallup polls. The results of Gallup’s annual Work and Education poll suggest that 61 percent of Americans believe children educated in charter schools receive an “excellent” or “good” education -- ranking charter schools above public schools and homeschooling, but behind independent private and parochial schools.

Despite increasing popularity, little indicates that charter schools are inherently better than public schools overall. A compilation of research showing that on average charter schools do not outperform their traditional public school counterparts also led charter-school proponents elsewhere to preach greater focus on accountability as these schools spread. There are, of course, pockets of excellence, school chains or specific places where charter school students outperform their peers -- but the same could be said for traditional public schools.

As this data trickles in, charter school advocates of all political stripes have become attuned to the possibility that they could lose political clout if they don't show results soon. For example the California Charter Schools Association last December called for districts to discontinue 10 charter schools the group cited as guilty of “consistent academic underperformance.” Last year, Washington, D.C., released its first charter school rankings in an effort to crack down on underperforming charter schools.

Amid the movement's internal soul searching regarding accountability for charter schools, a report released last December found that in nearly two decades -- as long as charter schools have existed -- only 3 percent have ever been closed for underperforming academically.

NAPCS points out that although the country’s 5,600-plus charter schools represent only 5 percent of American public schools, they are disproportionally represented on US News & World Report’s Best High Schools list -- 17 percent -- and Newsweek’s Transformative High Schools list -- 60 percent.

But critics have long contended that charter schools underserve students with disabilities, with a recent report providing numbers to back that claim. A U.S. Government Accountability Office released in June determined that charter schools do not enroll students with disabilities at the same rate as traditional public schools, despite federal laws that require all publicly funded schools to serve disabled students. The GAO report, commissioned by Rep. George Miller (D-Calif.), found that 11 percent of students enrolled in public schools during the 2009-10 school year had disabilities, compared to 8 percent of students in charter schools.

In recent years, state legislatures across the country have expanded charter access by lifting their caps on charters statewide. Last June, Maine passed a bill allowing for the creation of the state’s first charter schools, leaving only nine states in the country without a charter school law. In many cases, they were encouraged by the Obama administration, which incentivized charter flexibility in their Race to the Top competition.

“The cornerstone of the public charter school movement is to bring effective innovation into the teaching and learning process, to provide parents choices that better suit their children’s personal needs, and to allow educators the autonomy they deserve to best educate their students,” Nina Rees, president and CEO of the National Alliance for Public Charter Schools, said in a statement. “Twenty years later, and after more than 200 studies on charter schools, we’ve learned that eliminating unnecessary restrictions on how we teach, and breaking down the barriers of who can help children learn, has enhanced how children can achieve, learn, and develop.”

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