What happens when Congress overrides a veto?

When Congress overrides a veto, the bill becomes law despite the President's objection. A successful override requires a two-thirds vote in both the House of Representatives and the Senate, as set by Article I, Section 7 of the Constitution. After the President vetoes a bill, the bill returns to the chamber where it originated, accompanied by a written message explaining the President's objections. That chamber can then hold a vote on whether to override the veto. If two-thirds of those present and voting agree to override, the bill goes to the other chamber, which holds the same vote. If both chambers achieve the two-thirds threshold, the bill becomes law without the President's signature.

Override votes are difficult to achieve. Of more than 2,500 vetoes in American history, only about 110 have been overridden, roughly 4 percent. The two-thirds threshold typically requires significant bipartisan support, since neither party has held a two-thirds majority in either chamber for many decades. Override votes happen most often on bills with broad support that crosses party lines, such as defense authorizations, water projects, or technical legislation.

The first successful veto override came in 1845, when Congress overrode President John Tyler's veto of a revenue cutter authorization. Andrew Johnson holds the record for most overrides, with 15 of his 29 vetoes overridden during his contentious post-Civil War presidency. More recent overrides include Congress's override of George W. Bush's veto of a Medicare bill in 2008, of multiple bills during the Obama administration, and of Donald Trump's veto of the National Defense Authorization Act in 2020-2021. President Joe Biden saw one veto override during his term, on a measure relating to the federal regulation of certain financial issues.

Override votes can have significant political consequences. They demonstrate either bipartisan opposition to the President's position or the strength of the President's congressional support. A failed override vote (one that does not reach the two-thirds threshold) effectively confirms the veto, leaving the bill dead unless reintroduced and renegotiated. After a successful override, the bill takes effect just as it would have if the President had signed it. Federal agencies must implement the new law, and it becomes part of the U.S. Code.

The override mechanism is a central feature of the Constitution's checks and balances. It gives the President a meaningful veto power without making that power absolute, and it allows Congress to have the final word on legislation when it can muster sufficient support.