What is necessary to override a presidential veto?

To override a presidential veto, a two-thirds majority in both houses of Congress is necessary. This requirement is established by Article I, Section 7 of the U.S. Constitution, which outlines the legislative process, including how a veto can be overturned. Achieving a two-thirds majority ensures that there is substantial bipartisan support for the legislation in question, reflecting a broad consensus among lawmakers that the vetoed bill should become law despite the president's objections. This high threshold emphasizes the balance of power between the executive and legislative branches and serves as a check on the president's authority.

The other options do not meet the constitutional requirement. A simple majority, for instance, would allow for a relatively easy override, which could undermine the president's veto power. A majority in just the House of Representatives ignores the need for unity across both chambers of Congress. Lastly, a unanimous vote in the Senate is unrealistic and would be unnecessarily stringent, as it would allow a single senator to effectively block an override. Hence, the two-thirds majority reflects a reasonable compromise, requiring significant agreement across lawmakers from both the House and the Senate.