Hard, but not impossible. Jerry Ford felt that if Richard Nixon, who had been forced to resign over the Watergate scandal, were tried in court it would divide the nation. He decided to pardon Nixon so the U.S. could move ahead. O'Neill was right, but Ford believes yet he was right too. Every president elevated to the ranks of the greats has possessed an abundance of character, though never total.
Some weakness always inhabits the human soul.
But most scholars place Abraham Lincoln, Franklin Roosevelt and George Washington at the top of the list of those presidents who never wavered in the pursuit of the national interest above all else. When the officers with whom Washington had fought the Revolutionary War wanted to brush aside the weak and struggling new government and install Washington as sovereign, the old general quietly but firmly rejected the idea, though these were the men he loved the most. Washington's belief in the high cause he had led a strong, free democracy never left him. Presidents who have discernable character failings can at times do good work. Both John Kennedy and Richard Nixon, with great deeds on the books, nevertheless diminished themselves and their office by bad behavior and lawlessness.