Separation of powers is a core concept of America's Constitution. In the Founders' scheme, Congress, the courts, and the executive are independent branches of government, with their own roles and duties, intended to check one another.
But since 1984, the Supreme Court has hamstrung its own ability to act independently in the face of executive power. In Chevron U.S.A., Inc. v. Natural Resources Defense Council, the high court adopted a blanket presumption of deference to statutory interpretations put forth by regulatory agencies in any case where the statute was ambiguous, so long as the interpretation was reasonable.
