Every president has sought the advice of friends and allies outside of government at one time or another. Typically, these advisors serve as unbiased “sounding boards” for the president — ones who don't have a bureaucratic constituency or staff territories to protect. Most presidents turn to them infrequently, and only for counsel on specific matters for which they offer a special expertise.

Andrew Jackson was the first and perhaps only president to rely exclusively on counsel from a small circle of friends. This group was dubbed the “Kitchen Cabinet” by the press because they sneaked through the White House kitchen to meet with him. Jackson distrusted his formal cabinet, and didn't even meet with them until his third year in office. President Franklin Roosevelt had a similar group of informal advisors, whom he referred to as “the brain trust,” although he called on such advisors less frequently than did Jackson.

In recent times, the late Clark Clifford served as an informal counselor to every Democratic president from Harry Truman to Bill Clinton. Clifford was highly regarded in Democratic circles, and considered an invaluable presidential resource. Washington superlawyer Vernon Jordan was a close (and highly public) confidant of Bill Clinton.