What it actually is

A veto is the president saying "no" to a bill that both chambers of Congress have approved. It is a constitutional power written into Article I, Section 7.

When the president vetoes a bill, they normally return it to the chamber where the bill started with written objections (a veto message). That prevents the bill from becoming law unless Congress takes further action.

How it works

After Congress passes a bill, it goes to the president. The president can sign it into law, veto it, or take no action. If the president neither signs nor returns the bill within ten days while Congress is in session, the bill becomes law without the president's signature.

If the president returns the bill with objections, Congress can try to override that veto. Overriding a presidential veto requires a two-thirds majority vote in both the House and the Senate. If both chambers reach that two-thirds threshold, the bill becomes law despite the president's objection.

There is also a pocket veto. If Congress adjourns in a way that prevents the president from returning a bill, and the president does not sign it within the ten-day period, the bill does not become law and cannot be returned for an override.

A real example

A well-known historical example is President Andrew Jackson's veto of a bill to recharter the Second Bank of the United States. Jackson used the veto to block that legislation and to shape public policy.

That episode is often cited to show how a presidential veto can have policy and political consequences beyond the immediate bill.

Why it matters to you

Vetoes affect everyday life because they shape which laws take effect — including laws about taxes, benefits, regulation, and public spending. A veto can stop a law you support or block one you oppose.

Knowing how vetoes and overrides work helps you understand who ultimately decides public policy and why some bills fail even after passing both houses of Congress.

Common misunderstandings

A veto is not the same as the courts striking down a law; it is a political check by the president on legislation. It also is not the president unilaterally changing a law — overriding a veto requires a strong congressional majority.

The President does not have a general federal line-item veto (the power to cancel parts of a bill); some state governors have line-item veto powers, and a federal version has been found unconstitutional by the courts.