Timing matters. If the president does not sign or return a bill within ten days, excluding Sundays, it ordinarily becomes law. If Congress adjourns during that period in a way that prevents return, the bill fails through a pocket veto, which Congress cannot override because no returned bill exists. The president cannot cancel isolated provisions of a bill while approving the rest; the Supreme Court invalidated the statutory line-item veto because Article I requires approval or rejection of the bill presented.

The prospect of a veto shapes legislation before presentment. Members of Congress may revise a bill to secure presidential approval or enough votes for an override. A veto message can also frame political disagreement for the public. Yet the president does not possess a general power to enact substitute statutory language; executive recommendations and bargaining precede the formal choice among constitutional presentment options.

For a scenario, separate proposal, enactment, and administration. A threat to reject a pending bill is veto bargaining. A signed bill followed by executive implementation concerns execution. A two-thirds vote in only the Senate is insufficient for an override; each house must reach the threshold separately. Likewise, a presidential signing statement may explain an interpretation but does not exercise the Article I veto over selected words.

Video lesson: Separation of Powers and Checks and Balances: Crash Course Government and Politics #3