Legislative power refers to the ability to introduce, amend, and pass legislation; according to Article I of the U.S. Constitution, “all legislative Power herein granted shall be vested in a Congress of the United States.” In order to check the influence of the legislature, however, the framers of the Constitution gave the President the ability to approve of or veto any bill passed by the legislature. The Congress can override the President’s veto with a two-thirds majority in both chambers. In addition, the courts have the power to interpret the meaning of legislation and to declare it unconstitutional.
www.justicelearning.org, The United States Constitution, what it says, what it means, A Hip Pocket Guide (Oxford University Press)