If President Obama retained any credible claim to running a transparent administration, he surrendered it Wednesday when he asserted executive privilege over Justice Department documents pertaining to Operation Fast and Furious.

Congress had subpoenaed the material as part of its investigation into a scheme by the Bureau of Alcohol, Tobacco and Firearms and Explosives, by which the United States government intentionally permitted thousands of guns to be purchased in the United States and smuggled to Mexican cartels. At best, Obama’s action prevents Congress and the American people from understanding how and why Attorney General Eric Holder misled Congress about the operation in 2011. At worst, Obama has inserted himself personally into a scandal in order to protect his political appointees from the consequences of their actions.