The king of bad presidents: George W. Bush 

It's an American tradition: Whenever a president leaves office, people start debating how he stacks up against his predecessors. (Note: The use here of "he" and "his" isn't sexist exclusion, but a reflection of U.S. history) This time, though, there's a big difference. As President George W. Bush gets ready to leave the White House, it says a lot that the most frequently asked question about his place in history is whether he's the worst president ever, or just in the top five or six.

America has had more than its share of mediocrities in the White House, so how do you determine which was the worst? One way is to systematically compare the mistakes, weaknesses and failures of the presidents historians agree should have stayed home.

Historians generally cite four characteristics that can land a president on the "one of the worst" tally: 1. Sins of omission and/or incompetence; 2. Abuse of power; 3. Warmongering; and 4. Corruption. Some historians also consider poor personal character an indicator, but frankly, considering Bush's spoiled-fratboy-cum-county-sheriff persona and lifelong pattern of serial screw-ups, well, I've only got so much room for this article. So, let's look at how Dubya stacks up in the four other categories, compared to his fellow bad presidents.

Sins of omission and/or incompetence

Some presidents wind up on the Worst Presidents list because, figuratively speaking, they fiddled while Rome burned. Others were just inept. Some managed to do both. During the 12 years before the Civil War (1849-61), four awful, do-nothing presidents in a row -- Zachary Taylor, Millard Fillmore, Franklin Pierce and James Buchanan -- let the nation drift toward Civil War. Taylor and Fillmore were merely incompetent; Pierce stayed drunk; and Buchanan may have been the worst of all, not even bothering to act when Southern states started declaring their secession from the United States.

In the 20th century, Herbert Hoover (1929-33) was the poster boy for presidential sins of omission. When the Depression set in, he lowered taxes and began a few measly public works projects, but otherwise simply sat on his hands, acted cranky and refused to provide any actual relief to suffering citizens.

Among incompetent presidents, Warren G. Harding (1921-23) was the last century's archetype: a dimwitted, poker-playing skirt chaser who let himself be manipulated by his cronies and appointees while they raided the federal treasury. At least Harding, who died in office, knew he was incompetent, as he later revealed in a diary admission: "I am not fit for this office and should never have been here."

Jimmy Carter (1977-81) came to Washington as a reform-minded maverick with new ideas. Carter had a major, unforeseen problem, though: He had little idea of how to pull strings in D.C., and Congress wasn't about to show him. Carter floundered around for a couple of years, and his presidency was dead in the water by '79.

Last month, the Pew Research Center surveyed U.S. adults to name one word that best described their impression of Bush. The most common response? "Incompetent." How can any honest observer disagree? Bush's appointment of incompetent cronies to important positions (paging "Brownie" and Alberto!) and then failing to oversee their performance, led directly to two critical mistakes: FEMA's ruinous post-Katrina performance and the rampant politicization of the Justice Department. Add Bush's blithe dismissal of pre-9/11 warnings of impending attacks, plus his stubborn refusal to admit how badly the Iraq war was going until it was almost too late, and you're looking at a major-league incompetent.

Abuses of power

At various times, usually during a crisis, some presidents have abused the office -- as well as the Constitution and freedom itself -- in various ways. Ironically, two presidents usually rated among the greatest were guilty of serious abuses of power during wartime. During World War II, Franklin Roosevelt (1933-45) had Japanese-Americans moved into relocation camps for the duration of the war. Abraham Lincoln (1861-65), in the Civil War, suspended habeas corpus (a basic common law of Western governments since the 13th century, which protects people from being imprisoned indefinitely without being charged with a specific crime).

In 1798, the second president, John Adams (1797-1801), convinced Congress to pass the Alien and Sedition Acts, which heavily restricted the rights of government critics; Adams paid the price for his thin skin when Thomas Jefferson defeated him in the next election. In similar fashion, Woodrow Wilson (1913-21) presided over the enforcement of the shameful Sedition Act of 1918, which criminalized radical criticism of the government, and resulted in the arrest and attempted illegal deportation of more than 10,000 people. Wilson's affronts to democracy make America's modern political boogeyman, Richard Nixon (1969-74), look good by comparison. But not too good. Tricky Dick, after all, tried to stop publication of the Pentagon Papers, which detailed how the United States had become involved in Vietnam; ordered burglaries and wiretapping of his political adversaries; and directed coverups whenever his minions were caught.