News article explains the constitutional mechanics and history of presidential vetoes following midterm elections

The president's veto power serves as a primary constitutional check against legislation passed by Congress, requiring a two-thirds majority in both chambers to override a regular veto or leaving pocket vetoes absolute when Congress adjourns.

• •Article I, Section 7 of the U.S. Constitution grants the president the authority to veto legislation passed by Congress.
• •The president has 10 days, excluding Sundays, to act on legislation before it automatically becomes law.
• •Since 1789, 38 of 45 presidents have exercised veto authority a total of 2,576 times.
• •Congress has overridden presidential vetoes 111 times, accounting for 4.3% of all vetoes.
• •A regular veto can be overridden by a two-thirds vote in both the House and the Senate.
• •President George Washington issued the first regular veto on April 5, 1792.
• •The first successful congressional override occurred on March 3, 1845, overriding President John Tyler's veto of S. 66.
• •A pocket veto is an absolute veto that occurs when the president receives a bill but cannot return it to an adjourned Congress within the 10-day period.
• •Pocket vetoes are not subject to the congressional veto override process.
• •Donald Trump has vetoed 12 measures as president, with only one overridden.