The President's primary role in the legislative process is to sign or veto legislation passed by Congress. This power is known as the veto power.

A veto is a refusal by the President to sign legislation passed by Congress. This prevents the legislation from becoming law.

There are three types of vetoes: regular veto, pocket veto, and line-item veto. A regular veto is a refusal by the President to sign legislation within ten days of receiving it. A pocket veto is a refusal by the President to sign legislation after Congress has adjourned. A line-item veto is a refusal by the President to sign specific provisions of a bill while approving the rest of the bill.

If the President vetoes a bill, it is sent back to Congress for reconsideration. Congress can override the veto with a two-thirds vote in both the House and the Senate.

If the President pocket vetoes a bill, it is killed and cannot become law. Congress cannot override a pocket veto.

If the President line-item vetoes specific provisions of a bill, those provisions are killed and cannot become law. Congress cannot override a line-item veto.

Congress can override a veto with a two-thirds vote in both the House and the Senate.

Congress rarely overrides a veto. Since 1945, Congress has overridden only 11% of presidential vetoes.

The purpose of the veto power is to prevent Congress from passing legislation that the President disagrees with. The President can use the veto power to block legislation that he or she believes is harmful to the country.

The veto power has been used more frequently in recent years. In the past 50 years, presidents have vetoed an average of 7 bills per year. In the past 10 years, presidents have vetoed an average of 12 bills per year.

The veto power has been criticized for giving the President too much power, for being able to block legislation that is supported by the majority of Americans, and for leading to gridlock in government.

The veto power has been defended on the grounds that it ensures that legislation is carefully considered by the President, that it prevents Congress from passing legislation that is harmful to the country, and that it promotes compromise between the President and Congress.

The line-item veto was first used by a President in 1996, when President Bill Clinton used it to veto specific provisions of a spending bill.

President Bill Clinton used the line-item veto most frequently. He used it to veto specific provisions of 37 bills during his time in office.

The line-item veto was declared unconstitutional by the Supreme Court in 1998 in the case Clinton v. City of New York.