Yes, or in the military favoured way of shortening everything =
ADCs. They are there to serve the president, especially in
ceremonal events. Kinda like a high ranking runner. 
In a pinch they can throw themselves over the president to protect
him.
But usually those appointed are high profile high fliers. A few
years back (quite a few years) a commando Capt Bernie something was
appointed. Ne moved up the ranks quite quick.
