Until now, the political system and voters haven’t really held prosecutors accountable. About 95 percent of incumbent prosecutors won reelection, and 85 percent ran unopposed in general elections, according to data from nearly 1,000 elections between 1996 and 2006 analyzed by Ronald Wright of Wake Forest University School of Law.

But prosecutors are enormously powerful in the criminal justice system. They decide which laws will actually be enforced, with almost no checks on that power outside of elections. For instance, in 2014 Brooklyn District Attorney Kenneth Thompson announced that he will no longer enforce low-level marijuana arrests. Think about how this works: Pot is still very much illegal in New York, but the district attorney flat-out said that he will ignore an aspect of the law — and it’s completely within his discretion to do so.