Except as may be otherwise expressly provided in this Act, all powers and authorities conferred by this Act shall be cumulative and additional to and not in derogation of any powers and authorities otherwise existing. Notwithstanding any other evidences of the intention of Congress, it is declared to be the controlling intent of Congress that if any provisions of this Act, or the application thereof to any persons or circumstances, shall be adjudged by any court of competent jurisdiction to be invalid, such judgment shall not affect, impair, or invalidate the remainder of this Act or its applications to other persons and circumstances, but shall be confined in its operation to the provision of this Act, or the application thereof to the persons and circumstances directly involved in the controversy in which such judgment shall have been rendered.