Why would Buchanan endorse Bush? The president believes in a host of things that Pat utterly rejects, like democracy as a universal goal for humankind and an end to racism. Are candidates allowed to reject endorsements?
I don't see too much evidence that Bush supports democracy for everyone in the world. I hardly see him making a big push for democracy in Saudi Arabia, the Sudan, China, Pakistan, etc.
Bush does not support the concept of every country in the world becoming a democracy. That's why I don't like his foreign policy. He supports what is best for big business, plain and simple.