What is 'presidential greatness'?

The article "What is 'presidential greatness'?, written by Joseph Ellis, Aida Donald, Joan Hoff, H.W. Brands, and Richard Reeves, explores the ideas of what makes a president great, comparing some points in common between great presidents the United States had. As Truman said:  "A leader needed a true heart, a strong mind, and a great deal of courage." 'Roosevelt, who probably understood the presidency better than anyone else, was the greatest president of the 20th century because he knew what people wanted from the highest office in the land: action, words and optimism. As the article always says, and is the biggest truth when they are talking about great presidents, in good times or bad, a president is expected to do something! Sometimes he does the right thing and becomes great for it. Can also be observed that great presidents in history usually were involved in some war or conflict; but, as Aida Donald said:  "No, Franklin Roosevelt was a great president before World War II started. His domestic program had already made him a great president."
     Wartime Presidents are regarded by Americans as the greatest Presidents. That is what we discover when we examine the polls. Americans revere wartime Presidents. That’s the essence of  the great presidents in history. To Americans, a great President is heavily associated with war. It doesn't affect his greatness that Lincoln started the war, for example, which, if you think about it, should detract from his greatness. Wilson got the country into World War I and he ranks number 6. Franklin Roosevelt got the country into World War II and he ranks number 2. Their high rankings are also associated with the fact that they presided over the country during large-scale wars. Maybe it is all because, during a war, people feelings are more easily controlled, and the government could try to shape their opinion in favor to the president, creating a proud of their nation and its leader, during a war. As people usually say:  "anybody can grow up to be President." But, not everybody is cut out to be President. It takes a special kind of person, someone tough, smart, and driven, just to run for the job. It takes still more talent and character to hold up under the pressures of life in the White House.