How the Veto Works
Once both houses of Congress approve the same version of a bill or joint resolution, it goes to the president, who has 10 days (not including Sundays) to act on that legislation. If the president takes no action on a bill within 10 days, and Congress is in session, the bill automatically becomes law.
In the case of a regular veto, the president returns the piece of legislation to Congress within 10 days without signing it, usually with a memorandum explaining why he is rejecting the bill, known as a “veto message.”
Once a president has sent a bill back to Congress, he cannot change his mind and ask for it back. (Ulysses S. Grant tried to do this twice during his presidency, but Congress refused to comply.)
Pocket Veto
If Congress adjourns within 10 days after giving the president a bill, the president can exercise what’s known as a “pocket veto” by choosing not to sign the bill, or effectively putting it in his pocket. In this case, the bill will not become law, and Congress must begin the process all over again if it wants to revive the legislation.
The pocket veto is an absolute veto, which Congress cannot override. Article 1, Section 7 of the Constitution provides for this pocket veto power, stating that “the Congress by their adjournment prevent its return, in which case, it shall not be law.” Over the years, debate over the meaning of “adjournment” resulted in several federal court cases involving the pocket veto.
In the early 1970s, after both Richard Nixon and Gerald Ford attempted to use the pocket veto during brief adjournments during a congressional session, the U.S. Court of Appeals for Washington, D.C. ruled that the president could not use the pocket veto during short congressional recesses, as long as Congress appointed an officer to receive an ordinary veto message during such a recess.
How Can Congress Override A Presidential Veto?
Congress can override a regular presidential veto with a two-thirds vote of those present in both the House and the Senate. As of 2014, presidents had vetoed more than 2,500 bills, and Congress had overridden less than 5 percent of those vetoes.
The Constitution does not give the president the ability to reject parts of a bill and approve the remainder—or line-item veto power—which most state governors have. Since the 1870s, more than 100 amendments have been proposed to change this, but none have been passed. In 1995, Congress passed a law giving the president the line-item veto, but the Supreme Court later ruled it unconstitutional on the grounds that it gave the president more power than the Constitution allowed.