I once shared a flat with a mature (in most senses of the word) philosophy student in Glasgow, who was the first person who really made clear to me that the timescales for judging things on a historical basis are rather longer than recent electoral results. That caveat aside, it's difficult not to enjoy some schadenfreude at George W. Bush's expense on seeing the results of a recent Presidential Survey by C-SPAN over in the states.
Arguably the most important measures are Economic Management (i.e. managing the domestic agenda) and International Relations (managing the foreign agenda), and Dubya ranks extremely poorly on both (40 and 41 out of 42, respectively). Buchanan and Hoover, both have some responsibility for financial crises and in Buchanan's case their Civil War, rank lower on Economic Management.
With respect to International Relations, I was curious as to just how
W. H. Harrison had managed to do an even worse job. Apparently he was only at the top there for 32 days, so I feel comfortable saying that in the opinion of American presidential historians, Dubya was indeed their worst President ever as far as the world outside the US border would be concerned.
Not that I'm saying anything particularly novel here. But at least the next time an American chooses to take offense at a comment about Dubya, or in other words the fact that people do indeed have opinions about countries that are not their own, I can point out that their own experts agree :)