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Obama is better than his supporters. He does indeed seem to want to be more informed about issues, not circled by sycophants, not swayed by emotion over reason. This is not true for many of of the people who supported him in the primary over Clinton. They are in love with the feeling of being part of a movement and are not so willing to find out about the nitty gritty aspects of solving problems here and abroad. They resist knowing more about the world and its problems because facts have a way of getting in the way of enjoying their good feelings about Obama and being part of the joyful crowd ready for The One (to quote Oprah).
Hillary did all she can do to bring her supporters to Obama. She made the argument in broad ideological and cultural terms. Just think about it, could McCaine quote Harriet Tubman and reference Seneca Falls even if he wanted to?
Any thoughtful person who supported Hillary will of course vote for Obama in the election because essentially, being thoughtful, the stance of being thoughtful is what was at the heart of Hillary Clinton's candidacy. Emotion was at the heart of Obama's movement-- though Obama himself does indeed seem thoughtful. However, she has been thoughtful longer and to this voter seems more knowledgable than Obama.
As for making the specific argument that he Obama is ready to be Commander in Chief, that is an argument that must be made by himself.