Why are Presidents Grant, Andrew Johnson, Herbert Hoover, Lyndon Johnson and Richard Nixon judged hard ?

If each of these great men had been elected to more terms they would have enacted change for the nation. Nixon ended the Vietnam War after Johnson started bombing non-stop. Hoover would have turned around the economic effects of the Great Depression. Grant deserved better treatment as a War hero. Andrew Johnson was right in being open and fair to the Confederates.