Per his Wiki page, he is very anti Trump and also pro Iran.
Steven Simon is a former United States National Security Council senior director for the Middle East and North Africa.[1] He also previously served as the Executive Director IISS-US and Corresponding Director IISS-Middle East and as a Senior Fellow at the Middle East Institute based in Washington, D.C.[3] He was Hasib J. Sabbagh Senior Fellow for Middle Eastern Studies, at the Council on Foreign Relations. He was a Spring 2008 Berlin Prize Fellow. Steven Simon is now a visiting professor at Colby College in Maine.
HOW do people like this clear the background check?
His background puts him in a position to have lots of contacts in the current bureaucracy, and thus be a prime candidate for insiders to leak to.