The president of the United States of America, Joe Biden, quit the re-election race and endorsed the country鈥檚 vice-president Kamala Harris as democrat presidential candidate on Sunday ahead of the election scheduled to be held in November.
Biden is the second US president to drop out of a re-election race, reports CNN.
In 1968, US president Linden B Johnson, suddenly announced his withdrawal from the race during a scheduled speech on Vietnam.
Vice-president Hubert Humphrey stood in after Johnson quit. However, senator Robert F Kennedy also vied for the nomination but did not survive the primary season. After he won victory in California primary, Kennedy was assassinated at the Ambassador Hotel in Los Angeles in June.
Although Hubert Humphrey won a massive support from delegates to become the nominee, democrats tasted defeat that year.
Republican Richard Nixon defeated Humphrey to become the 37th US president in 1968.