Thomas Jefferson had well-founded doubts about the constitutionality of the Louisiana Purchase that he endorsed. [read post]

But, said the Court: [W]e are here dealing not alone with an authority vested in the President by an exertion of legislative power, but with such an authority plus the very delicate, plenary and exclusive power of the President as the sole organ of the federal government in the field of international relations—a power which does not require as a basis for its exercise an act of Congress . . . . [read post]