Ben Carson has no experience running a federal agency and especially in the areas covered by the office of Housing and Urban Development. So naturally, he'll be the Secretary of that department.
I've seen a lot of comments that the pick is because Trump figures he has to have a black guy somewhere in his cabinet. But Jonathan Chait thinks the idea is to put someone there who will never let the needs of the poor and disadvantaged get in the way of enriching wealthy developers…like, say, Donald Trump and his friends.