It's not mandatory, but most presidents attempt it.
Be elected again.
No
President's term is four years but can be re-elected for a second term.
McKinley was first elected in 1896 and elected to a second term in 1900.
1804
1793
yes
He was president for a full term (four years) then was shot soon after he was elected into his second term.
The election of 1996 was Bill Clinton's second term as President of the United States.
Elected 1800 & 1804
John Kennedy was elected president after Dwight's second and last term.
1819 was not an election year. In 1820, James Monroe was elected to a second term.