Which of the following statements best describes how the constitution best describes how the constitution provides for a federal system of government? -The U

Which of the following statements best describes how the constitution best describes how the constitution provides for a federal system of government?
-The U.S. Constitution provides for representative government mainly?
-During U.S. history, which of the following constitutional clauses has played the least significant role in the expansion of federal authority?
-Over the course of U.S. history, the federal system has become increasingly "nationalized" in the sense that the federal government's authority has expanded relative to the power of the states. Which factor has been least important in this development?
-in comparing the Supreme Court rulings upholding the New Deal programs with the Supreme Court ruling upholding the 2010 health care reform act, which statement is true?