act as President, or the manner in which one who is to act shall be selected" if there is no president-elect or vice president-elect by January 20. It also clarifies that if there is no president-elect on January 20, whoever acts as president does so until a person "qualified" to occupy the presidency is elected to be president. Interaction with the Twenty-second Amendment The Twelfth Amendment explicitly states the constitutional requirements as provided for the president also apply to being vice president and the Twenty-second Amendment bars a two-term president from being elected to a third term, but it is unexplicit whether these amendments together bar any two-term president from later serving as vice president as well as from succeeding to the presidency from any point in the United States presidential line of succession. Some contend that the Twelfth Amendment concerns qualification for service, while the Twenty-second Amendment concerns qualifications for election, and thus a former two-term president is still eligible to serve as vice president. Some legal scholars propose the contention above would inadequately consider the opportunity it affords for one to serve as president more than two terms plus "[acting] as President, for more than two years," resulting in a violation of the Twenty-second Amendment. The interaction between the two amendments has not been tested, as no twice-elected president has ever been nominated for the vice presidency. Hillary Clinton jokingly said during her 2016 presidential campaign that she had considered naming her husband, twice-elected former president Bill Clinton as her vice presidential running mate, but had been advised it would be unconstitutional. This constitutional ambiguity allowed for speculation in 2020 about whether twice-elected former president Barack Obama was eligible to be vice president. Elections since 1804 Starting with the election of 1804, each presidential election has been conducted under the Twelfth Amendment. Only once since then has the House of Representatives chosen the president in a contingent election, in the 1824 election as none of the four candidates won an absolute majority (131 votes required at the time) of electoral votes: Andrew Jackson received 99 electoral votes, John Quincy Adams (son of John Adams) 84, William H. Crawford 41, and Henry Clay 37. As the House could consider only the top three candidates, Clay was eliminated, while Crawford's poor health following a stroke and heart attack made his election by the House unlikely. Jackson expected the House to