I, § 1—requiring all legislative powers to be vested in a Congress consisting of a Senate and a House of Representatives—and § 7—requiring every bill passed by the House and Senate, before becoming law, to be presented to the president, and, if he disapproves, to be repassed by two-thirds of the Senate and House—represents the Framers' decision that the legislative power of the Federal Government be exercised in accord with a single, finely wrought and exhaustively considered procedure