According to a new study from the American Enterprise Institute, media coverage of public charter schools grew more opinionated and negative from 2005 to 2015.

The negative turn occurred even though the public's view of charters grew much more positive during the same time frame. According to Gallup polls, 49 percent of the public supported charter schooling in 2005, rising to 64 percent in 2015.

In 2005, almost three-quarters of charter school articles were neutral. By 2015, that portion had fallen nearly to half. The share of negative articles grew from 12 percent to 28 percent.

The study examined coverage in mainstream newspapers, such as the New York Times and the Washington Post, education outlets, such as Education Week, and various regional papers.

Interestingly, the study found that the New York Times had the most positive coverage of charter schools in 2005. It has since grown more negative, but still has more positive coverage than the Washington Post. The Washington Post's turn toward negative coverage is largely driven by negative opinion pieces.

Education Week, which the study calls "the K-12 education newspaper of record," grew more positive in its news coverage of charters, but turned slightly negative in its opinion pieces.

Race also became a more prominent issue in charter school articles over time, rising from 7 percent of articles in 2005 to 16 percent in 2015. Race-related articles were generally positive, though trended toward negative as time went on.

"The media have an integral part to play in relaying education news to families and participating in democratic debates about schooling," the authors write. "With that in mind, it is useful for researchers to examine the media's take on these issues, explore the dynamics of press coverage, and ensure that discussions about media bias or balance are informed by consideration of the factual record."

The study was authored by Frederick Hess, Kelsey Hamilton and Jenn Hatfield at AEI.

Jason Russell is a commentary writer for the Washington Examiner.