What Is a Presidential Veto? How It Works and Why Congress Rarely Overrides It

Before a bill becomes a law in the United States, it has to get through one more person: the president.

Most of the time that is a formality. The president signs the bill, and it takes effect. But the Constitution gives the president another option, and it has become one of the most important powers in Washington this week, now that Democrats have won control of Congress. That option is the veto.

What a veto is

A veto is the president's power to stop a bill passed by Congress from becoming law. It comes from Article I, Section 7 of the Constitution. When Congress passes a bill, it is sent to the White House. The president then has 10 days, not counting Sundays, to act on it. He can sign it, in which case it becomes law. Or he can send it back to Congress, usually with a message explaining his objections. That second choice is the veto.

If the president does nothing and Congress is still in session when the 10 days end, the bill becomes law without his signature.

How Congress can fight back

A veto is not final. Congress can override it, but the bar is high. Both the House and the Senate have to vote again on the bill, and each needs a two-thirds majority. If both succeed, the bill becomes law despite the president's objection. If either falls short, the veto stands.

Two-thirds is a much harder target than the simple majority needed to pass a bill. In practice, it means a bill needs support from many members of the president's own party.

The pocket veto

There is also a quieter version. If Congress adjourns during the 10-day window and the president does not sign, the bill dies. This is called a pocket veto, and because Congress is not in session to vote again, it cannot be overridden. USAFacts says about 41% of all presidential vetoes in history have been pocket vetoes, although modern presidents and Congresses disagree about when one is valid.

How often it is used, and how often it is beaten

George Washington issued the first regular veto on April 5, 1792. Since then, presidents have vetoed about 2,600 bills, according to USAFacts and Ballotpedia. Franklin D. Roosevelt holds the record with 635. Congress has overridden only 112 of them, around 4%.

That low number is the point. A veto is often less about the vote that follows and more about the threat that comes first. If Congress knows a bill will be vetoed and cannot be rescued, it may never send it. USAFacts also notes that vetoes are most common when power is divided, when the president and Congress are not controlled by the same party.

Why it matters right now

Starting January 3, power in Washington will be divided. Democrats won the House and the Senate in the midterms, while Republican Donald Trump remains in the White House for two more years.

Trump has been open about how he plans to use the power. Before the election he said he would become "Mr. Veto" if Democrats won, and he has also threatened to veto everything. After the results came in, he said he would work with Democrats. Many of his critics are watching to see which version shows up.

The math is the reason the veto matters. Democrats will not have two-thirds of either chamber, so they cannot override Trump on their own. NBC News reported that House Democratic leader Hakeem Jeffries has four priorities: reversing Medicaid cuts, extending Affordable Care Act subsidies, taking back Congress's say over tariffs and ending the war with Iran. Each would need either Trump's signature or a veto-proof majority. The Senate adds another hurdle, since most bills there need 60 votes to advance.

That does not make Democrats powerless. A veto only applies to bills, and Democrats can still hold hearings, issue subpoenas and use their control of spending to gain leverage in budget fights. But it does mean the next two years may be defined more by what Congress investigates and blocks than by what becomes law.

Frequently asked questions

Can Congress ignore a veto?

No. It can override it with a two-thirds vote in both chambers. Otherwise the bill does not become law.

Has Trump vetoed bills before?

Yes. The first veto of his second term was of a bill sponsored by Rep. Lauren Boebert, according to Colorado Public Radio.

Can a president veto part of a bill?

No. A president must accept or reject the whole bill. Congress passed a line-item veto law in 1996, but it was struck down by the Supreme Court in 1998.

Does a veto need a reason?

No. A president can veto a bill for any reason, though he usually sends Congress a message explaining his objections.

Related coverage

Sources: U.S. Constitution, Article I, Section 7; USAFacts; Ballotpedia; the Congressional Research Service; U.S. House of Representatives History; NBC News; Colorado Public Radio, November 2026.