Title: Nebraska Legislature
Content:  The Legislature is responsible for law-making and appropriating funds for the state. The governor has the power to veto any bill, but the Legislature may override the governor's veto by a vote of three-fifths (30) of its members. The Legislature also has the power, by a three-fifths vote, to propose a constitutional amendment to the voters, who then pass or reject it through a referendum.
Title: Constitutional law of the United States
Content:  a President of the United States of America. Enumerated powers of the President Several important powers are expressly committed to the President under Article II, Section 2. These include:  The Presentment Clause (Article I, Section 7, cl. 2-3) grants the president the power to veto Congressional legislation and Congress the power to override a presidential veto with a supermajority. Under the clause, once a bill has been passed in identical form by both houses of Congress, with a two thirds majority in both houses, it becomes federal law. The president approves or rejects a bill in its entirety; he is not permitted to veto specific provisions. 
Title: United States Congress
Content:  Article One of the United States Constitution states, "All legislative Powers herein granted shall be vested in a Congress of the United States, which shall consist of a Senate and House of Representatives." The House and Senate are equal partners in the legislative process – legislation cannot be enacted without the consent of both chambers. However, the Constitution grants each chamber some unique powers. The Senate ratifies treaties and approves presidential appointments while the House initiates revenue-raising bills. The House initiates impeachment cases, while the Senate decides impeachment cases. A two-thirds vote of the Senate is required before an impeached person can be removed from office. The term Congress can 
Title: Federal government of the United States
Content:  The House and Senate each have particular exclusive powers. For example, the Senate must approve (give "advice and consent" to) many important presidential appointments, including cabinet officers, federal judges (including nominees to the Supreme Court), department secretaries (heads of federal executive branch departments), U.S. military and naval officers, and ambassadors to foreign countries. All legislative bills for raising revenue must originate in the House of Representatives. The approval of both chambers is required to pass all legislation, which then may only become law by being signed by the president (or, if the president vetoes the bill, both houses of Congress then re-pass the 
Title: New Jersey Legislature
Content:  The Legislature has the power to enact laws by a majority vote of both houses, subject to the Governor of New Jersey's ability to veto a bill. A veto may be overridden by the Legislature if there is a two-thirds majority in favor of overriding in each House. By a three-fifths vote of each house, the Legislature may propose an amendment to the State Constitution. Alternatively, it may propose an amendment by a majority vote two consecutive years. In either case, the amendment is placed on the ballot and must be approved in a referendum to become valid as a part of the constitution. The Legislature is also empowered to ratify amendments to the U.S. Constitution, appoint the State Auditor, judge the elections and qualifications of its members, and institute and conduct impeachment proceedings against State officials. The Senate has the sole authority to confirm or reject gubernatorial nominees for judicial and some executive positions.
Title: Veto
Content:  Proposed legislation (bills) that is passed by both houses of Congress is presented to the President, in their capacity as head of the Executive Branch of the US federal government. If the President approves of the bill, he or she signs it into law. According to Article 1. Section 7 of the Constitution, if the President does not approve of the bill and chooses not to sign, they may return it unsigned, within ten days, excluding Sundays, to the house of the United States Congress in which it originated, while the Congress is in session. The President is constitutionally required to state any objections to the bill in writing, and the Congress is required to consider them, and to reconsider the legislation. Returning 
Title: New York State Legislature
Content:  The Legislature is empowered to make law, subject to the governor's power to veto a bill. However, the veto may be overridden by the Legislature if there is a two-thirds majority in favor of overriding in each House. Furthermore, it has the power to propose New York Constitution amendments by a majority vote, and then another majority vote following an election. If so proposed, the amendment becomes valid if agreed to by the voters at a referendum.
Title: United States
Content: Legislative: The bicameral Congress, made up of the Senate and the House of Representatives, makes federal law, declares war, approves treaties, has the power of the purse, and has the power of impeachment, by which it can remove sitting members of the government. ; Executive: The president is the commander-in-chief of the military, can veto legislative bills before they become law (subject to congressional override), and appoints the members of the Cabinet (subject to Senate approval) and other officers, who administer and enforce federal laws and policies. ; Judicial: The Supreme Court and lower federal courts, whose judges are appointed by the president with Senate approval, interpret laws and overturn those they 
Title: Maine Legislature
Content:  As the legislative branch of the Maine state government, the Legislature has the power to make laws, subject to a veto by the Governor. The Legislature, however, by a vote of two-thirds in each house, may override the veto. The Legislature also has the power to propose constitutional amendments by a vote of two-thirds in each house; the proposal must be approved by a majority of voters in a referendum in order to be passed. Unlike other states, the Legislature is responsible for electing the Attorney General, State Treasurer, and Secretary of State. Most states give this responsibility to gubernatorial appointments, or an election by the people at large.
Title: President of the United States
Content:  override a presidential veto, it requires a two-thirds vote of both houses, which is usually very difficult to achieve except for widely supported bipartisan legislation. The framers of the Constitution feared that Congress would seek to increase its power and enable a "tyranny of the majority," so giving the indirectly-elected president a veto was viewed as an important check on the legislative power. While George Washington believed the veto should only be used in cases where a bill was unconstitutional, it is now routinely used in cases where presidents have policy disagreements with a bill. The veto – or threat of a veto – has thus evolved to make the modern presidency a central part of the American legislative process. Specifically, 

Question: who has the power to approve or veto legislation constitution?
Answer: the President.