What would happen if the Supreme Court did not have the power to review acts of Congress?

If the Supreme Court were not able to review the legislation of Congress, it would not go completely unchecked. First, assuming that Articles I and II of the Constitution remained intact, the president could veto any legislation he or she chose to veto. Congress needs a two-thirds majority of the House of Representatives and Senate to override a presidential veto, which can be difficult to achieve. Second, the president has some discretion on implementing and enforcing a law. How much discretion is not clear, since one decision that might have determined that is not forthcoming with only eight members currently on the Supreme Court.  Third, the people, who may have some reason to be unhappy with legislation, have the option of voting out those who passed the legislation.