Separation of Powers: An Overview. Matthew E. Glassman, Analyst on the Congress. January 8, 2016. Congresss role and operation in national politics is fundamentally shaped by the design and structure of the governing institution in the Constitution. One of the key principles of the Constitution is separation of powers. The doctrine is rooted in a political philosophy that aims to keep power from consolidating in any single person or entity, and a key goal of the framers of the Constitution was to establish a governing system that diffused and divided power. These objectives were achieved institutionally through the design of the Constitution. The legislative, executive, and judicial branches of the government were assigned distinct and limited roles under the Constitution, and required to be comprised of different political actors. The constitutional structure does not, however, insulate the branches from each other. While the design of the Constitution aims, through separation, to prevent the centralization of power, it also seeks the same objective through diffusion. Thus, most powers granted under the Constitution are not unilateral for any one branch; instead they overlap. The constitutional structure of separation of powers invites conflict between the branches, particularly between Congress and the President. The electoral structure of the federal government provides not only separate bases of authority, but also different bases of authority for political actors, as well as different time horizons. Likewise, the assignment of powers under the Constitution is not only overlapping, but also somewhat vague, creating inter-branch contests for power across many key functions of the government. Finally, numerous questions of authority are not even addressed by the Constitution.