The issue of Crisis Management is a crucial one in judging Presidential leadership, as what matters more than that in judging a President, or a governor of a state or a mayor of a city, all executive positions where the population depends on the abilities, skills, compassion, and empathy of such leaders.
So on that factor alone, Donald Trump is insured of being ranked the worst President ever, as he totally has failed in the present CoronaVirus Crisis, which may end up considered the greatest crisis since the Great Depression, World War II, and the Civil War!
Franklin Pierce and James Buchanan were unable to handle the issue of division between the North and the South over slavery in the 1850s, helping to lead to the Civil War.
Ulysses S. Grant and Warren G. Harding were totally incompetent in dealing with the issue of political corruption in the 1870s and the early 1920s.
Herbert Hoover was unable to resolve the crisis of the Great Depression in the early 1930s, as economic conditions worsened every month.
Andrew Johnson in the 1860s, Richard Nixon in the 1970s, and George W. Bush in the 2000s presided over governments that were highly inept and corrupt in so many ways.
But Donald Trump has been horrendous in all these way—inability to unite the nation in a crisis as with Franklin Pierce and James Buchanan; personally engaged in corruption in a wider way than Ulysses S. Grant, Warren G. Harding, and Richard Nixon; disastrous policies on so many issues as with George W. Bush; and total ineptitude in a difficult time in national life, as with Andrew Johnson and Herbert Hoover.
So Trump, without any debate possible, will rank as the absolute worst President we have ever seen in American history! Let us hope that the nation will overcome the CoronaVirus epidemic in decent shape, without too much loss of life, and that no foreign foe takes advantage of our weaknesses to present a threat on the scale of September 11. 2001 or December 7, 1941!