Political institutions are always works in progress. Their practical duties and aims as instruments of governance may not always match their constitutional blueprints or historical roles. Political offices might not always have the power to do what their constituent officers either need or want to do. A polity's assessment of whether the desired power is a need or a want may indeed mark a boundary between law and politics in the domain of institutional structure. The law gives, or is interpreted to give, political organs the tools they need to function effectively. They must fight for the rest.
The Supreme Court as a Constitutional Court,
Harv. L. Rev.
Available at: https://scholarship.law.columbia.edu/faculty_scholarship/663