By Paul Reynolds
World affairs correspondent, BBC News website
I suppose the underlying question here is whether George W Bush has been one of the worst US presidents.
Many people have already made up their minds.
For them, the invasion of Iraq was enough to put Mr Bush high on the list. And that was compounded by his lack of action elsewhere - with global warming and Hurricane Katrina as examples.
Others will want to wait a bit and see what history decides. History can improve the image of a presidency.
Harry Truman is the great example. His approval rating dipped even lower than Mr Bush's (though Mr Bush has registered a higher disapproval rating - a discrepancy due to a decline in the number of "don't knows").
The Truman years were full of epic events, from the dropping of the first atomic bomb, to the start of the Cold War, to the actual Korean War, to his dismissal of the popular Gen Douglas MacArthur.
The Chicago Tribune called for Truman to be impeached.
He appeared at times to be overwhelmed and he went down, but history has brought him up again and he is now generally seen as a gutsy president who took the right decisions.
Mr Bush is hoping for a similar vindication.
In the meantime, here are some of the candidates in the race for the bottom, in chronological order.
1. James Buchanan (President 1857-1861)
Buchanan failed to head off the Civil War. His position was weak, arguing on the one hand that the South should not secede and on the other that the North should not use force. It led to inaction and vacillation. Maybe he could not have succeeded, but he was not even seen to try.
2. Andrew Johnson (President 1865-1869)
In the aftermath of the Civil War, Johnson had a policy of punishing the Confederate leaders but letting off their followers. However, he is reckoned to have given too many concessions to the South, thereby laying the groundwork for the racial problems the United States subsequently experienced. He and Bill Clinton are the only two presidents to have been impeached. In Johnson's case it was over the power of presidents to dismiss cabinet members. Both were acquitted.
3. Warren Harding (President 1921-1923)
Harding was mired in scandal, because he appointed incompetent and corrupt cronies. His secretary of the interior, Albert Fall, was convicted of taking bribes in exchange for handing out oil leases on publicly-owned land and went to prison. Harding said he had less trouble from his political enemies than from his friends.
4. Herbert Hoover (President 1929-1933)
Hoover had done magnificent work during World War I, getting food into starving Belgium and later into a defeated Germany and even the Soviet Union. But his failure to combat the great depression when he became president led to his downfall - and to the interventionist approach of Franklin Delano Roosevelt.
5. Richard Nixon (President 1969-1974)
The only president to have resigned the office has to be on the list. His offence was obstruction of justice, arising from his attempt to cover up the Watergate break-in. He left office in disgrace.
There is also another way of looking at presidential reputations. This is to look at specific decisions they have taken. On this list appear some presidents whose historical place is otherwise strong. In 2006, historians gathered by the University of Louisville listed the "top 10 presidential errors".
1. James Buchanan's failure to stop the Civil War.
2. Andrew Johnson's decision to favour Southern whites after the Civil War.
3. Lyndon Johnson's escalation of the Vietnam War.
4. Woodrow Wilson's inability to get the United States into the League of Nations after the First World War.
5. Richard Nixon's role in the Watergate cover-up.
6. James Madison's war with Britain in 1812.
7. Thomas Jefferson's embargo on trade with Europe during the Napoleonic Wars.
8. John Kennedy's attempt to invade Cuba at the Bay of Pigs.
9. Ronald Reagan's sale of arms to Iran in the Iran-Contra scandal.
10. Bill Clinton's relationship with Monica Lewinsky.
Will George Bush's invasion of Iraq get on to a similar list in 20 or 50 years' time?
A British historian of American politics, Professor John Philip Davies of de Montfort University, says: "George Bush's problem is that he hasn't had many successes and he has made mistakes. Iraq and Afghanistan have not come out well and his hopes of becoming another Harry Truman must be in doubt."
Every failing president looks to Truman, he notes. Gerald Ford moved a bust of him into the White House.
I think time will be a great help to Bush Jr - his handling of Sept 11 was superb, he helped bring the economy back after the attacks
Kathy, Caledonia, MI, USA
In Professor Davies' view, Warren Harding was "one of the worst".
"He chose genuinely seedy characters for his cabinet and was deeply gullible. He looked the part, like an emperor whose face should be on coins, but he was dreadful at choosing his team," he says.
He also notes that Truman is not the only former president whose stock has risen over time.
"Richard Nixon is undergoing something of a rehabilitation in terms of policy - his opening to China, for example, and his decision to end the Vietnam War," he says.
"Jimmy Carter was seen as weak at the time but has been an excellent former president.
"Eisenhower is now seen by some as less of a 'do-nothing' president than a 'hidden hand', thanks to a favourable biography, which all presidents need.
"History can move a president up or down the table but I think its judgment is not hugely different from that of contemporaries."