William Henry Harrison became the first President to die in office, in 1841, and his death left a great deal of confusion about who should replace him as President. The vague language of the Constitution made it confusing as to whether the office of President should immediately devolve to the Vice-President, or whether the Vice-President should simply fulfill the responsibilities of President without the office or title. John Tyler, Harrison’s Vice-President, had himself inaugurated as President and acted quickly to ensure that his position as President could not be questioned, establishing the Tyler Precedent.

A candidate has to be a natural born citizen or a citizen of the United States at the time of the adoption of the Constitution, must be at least 35 years of age, and must have been a resident of the United States for at least 14 years. There is no requirement that a candidate be born in one of the 50 States. The requirement of a natural born citizen is widely interpreted to mean someone who is a citizen by virtue of their birth (e.g. to an American citizen parent), which does not necessarily have to occur in one of the 50 states. For example, John McCain could have been elected President in 2008 despite being born in the Panama Canal Zone.

The Constitution explicitly lays out the procedure for treaty making. After a treaty is negotiated by the President, it is sent to the Senate for approval.  of the Senate must vote yea for the Treaty to be ratified by the United States. A simple majority of the senate is not sufficient to approve a treaty.

The “line-item” veto was an attempt by a newly-Republican Congress to help bring federal spending under control in the mid-nineties. Essentially, Congress cobbled together a bill that would allow the President to strike individual portions of bills (generally budget measures), but sign the rest of the bill into law. One of the portions that Clinton removed, after being vested with this power, affected some “pork” that Congress secured for New York.

New York sued, hence the case. The Supreme Court held that this ability of the president violated the Presentment Clause of the Constitution; the President was not technically signing into law a bill that was passed by Congress.

Gerald Ford was a Congressman from Michigan and the House Minority Leader when he was appointed by President Nixon to replace Spiro Agnew as Vice President in 1973, after Agnew resigned. Nixon then resigned in 1974, elevating Ford to the office of President. This was the first time that something of this nature had happened and helped set a precedent for what happens it something prevents both the president and vice president from fulfilling their terms.

The constitution stipulates that the Senate must approve all treaties negotiated by the President. Granting of pardons, vetoing bills, and receiving foreign emissaries are solely the powers of the President.

The constitution lays out the powers and responsibilities of the office of the Vice-President. One of those is to cast the tie-breaking vote in case of a tie within the Senate.

In case the president commits crimes or fails in their duty as President, the constitution lays out the procedure to have the president removed from office. Trial in the House and then formal impeachment can be conducted by the Senate.

Part of the checks and balances, Congress has to power to override a presidential veto with a  majority vote in both Houses. This ensures that the President is checked in their authority.

If the Vice President must take over for the President in the case of death, the two-term limit does not apply to those years that they serve as President. Therefore, if the former Vice President ran and won the next two election cycles, they could legally serve more than 8 years.