Presidential Advisers' Testimony Before Congressional Committees: An Overview [November 18, 2009] [open pdf - 274KB]
"Since the beginning of the federal government, Presidents have called upon executive branch officials to provide them with advice regarding matters of policy and administration. While Cabinet members were among the first to play such a role, the creation of the Executive Office of the President (EOP) in 1939 and the various agencies located within that structure resulted in a large increase in the number and variety of presidential advisers. All senior staff members of the White House Office and the leaders of the various EOP agencies and instrumentalities could be said to serve as advisers to the President. […] Congress has a constitutionally rooted right of access to the information it needs to perform its Article I legislative and oversight functions. Generally, a congressional committee with jurisdiction over the subject matter, which is conducting an authorized investigation for legislative or oversight purposes, has a right to information held by the executive branch in the absence of either a valid claim of constitutional privilege by the executive or a statutory provision whereby Congress has limited its constitutional right to information."
CRS Report for Congress, RL31351