As a writer and academic who has actively followed US politics for over 40 years, I can honestly say that the state of the US presidency is now worse than it has ever been at any time since WW2. Much of the blame for this can be laid at the door of George W Bush, although some must devolve on other presidents from Nixon onwards.
If we are to assess George W., let us think about what history will say about him. His legacy will, of course, be overshadowed by Iraq. The desire to invade that country was present in the minds of Bush's closest advisers before his election. Note that I don't say Bush's mind, as I don't perceive him being capable of that sort of strategic thinking. My view is that he is a convenient mouthpiece for the groups of neo-Cons who had earlier served his Father whilst he was President, but whose ambitions were curtailed when Bush Snr failed to win a second term. The decision to actually invade was taken as soon as 9/11 gave the excuse. There are reported conversations confirming this.
This decision to force a war with Iraq has cost the US more than 3,000 lives (and the total will be much larger if the current insane 'surge' into urban guerilla warfare is fully implemented. The number of Iraqi dead is well into six-figures and the rate of killings is increasing. The decision cost the US all the sympathy it had gathered as a result of 9/11. This is a war which has now involved the US longer for than it was involved in WW2 and the War in Iraq is further away from being won today than it was on the day US troops first reached Baghdad. As a result, the world is a much more dangerous place for US citizens. The current president has squandered an immense legacy of goodwill which will take at least a generation to rebuild.
George W's other international contribution is his denial, at the behest of his oil industry friends, of the reality of glbal warming. This despite almost overwhelming evidence (growing for a quarter of a century or more) that the world's, and in particular the US's, use of fossil fuels is doing potentially irreversible harm to the globe. The impact of policy failure in this area will be felt for generations to come and will cost the lives of many millions of the world's poorest people as climate change really takes hold. This will also impact closer to home, again more heavily on the poor: Katrina reminded us of that. Katrina also reminded us of the degree of inefficiency and corruption in the federal administration headed by this president.
In budgetary terms, what will Bush be remembered for? A massive deficit, even larger than that built up by his father's predecessor, Ronald Reagan. This legacy to the US people will eventually catch up and have to be paid for. The impact will be on the public services necessary to the population at large's well-being. The very rich have become massively rich and are being taxed less than ever. The trickle down effect of this is an increased degree of division is society, a degree of division which an already divided country does not need.
In social terms, how will historians recall the Bush Junior years? Once other countries have shown the medical benefits to be gained from it, there will be incredulity about his refusal to countenance stem-cell research. This will help to set US medical research back in the world rankings, with the consequent knock-on on national prosperity.
In political terms, he will be remembered as the President who got the job by stealing an election with the aid of his brother. He will be remembered as the Governor who signed the death warrants of more US citizens that any other since that penalty was reintroduced. He will be remembered as the President who couldn't read a sentence on a speech prompt, and who, when he couldn't remember simple words, simply made them up. The man who made Gerald Ford seem elegant.
So, what about George W Bush?
History will not be kind to him. He will be remembered as a shallow man who became president because his father's advisers saw in him someone who could be manipulated into supporting his father's unfinished agendas, and whose brother stole an election for him. He will be remembered as the man who made the world less safe for all in the West, and particularly for those in the US. He will be remembered as the man who forgot the lessons of history and, especially, the lesson of Vietnam. He will be remembered as the man who made his friends immensely rich and US citizens at large poorer. He wil be remembered as the man who divided further an already divided country. He will be remembered as the man who refused to be guided by proven science, instead putting the profits of his friends above the interests of the world.
Quite simply, he will be remembered as the worst President of modern times.