United States government

Possible Cabinet positions in the Enclave are:
 * Secretary of Defence - DoD oversee US Armed Forces,
 * Secretary of Treasure - in Fallout world his Department still should oversee law enforcement agencies and among them - Secret Service,
 * may be just before the War - Secretary of Commerce, because of strong links with Poseidon consortium,
 * other known cabinet level administration officers are Vice-President and Administrator of the Environmental Protection Agency (latter one was present before the War and wasn't a member of the presidential line of succession).

Very likely Cabinet present in the Enclave is minimally staffed body (eg. the first American President appointed a Cabinet of four people).