Apparently, some Conservative Defeatists seems to be there too.
For people like Buckley, Buchanan, Hagel et al, their egos are way more important then what is good for the USA. To admit Bush was right would require them to set aside decades of hate for the Bush family as well as some of their tightly cherished political dogmas. Like most people, they would rather blame the one showing them their errors then admit the errors exist.
It one of the more sorry aspects of US politics is how often things are done because of the egos of the players rather then the best interests of the country.