Obama can't flout a military record, but his strengths, like McCain's, have a way of mirroring the president's shortcomings. Bush got where he is with the help of first-class family connections; Obama had to rise through brains and initiative. Bush regularly loses wrestling matches with the English language, while Obama expresses himself with unnerving fluency.
Bush becomes defensive and peevish when asked to answer the simplest questions about his policies; Obama never gets ruffled. Where Bush treats criticism like the Ebola virus, Obama conveys the impression that he hopes to learn from those who disagree with him.
The response of so many people to his message of unity comes partly from weariness with the administration's nonstop scorched-earth tactics. He conveys the novel view that Americans can disagree without hating each other. It's impossible to imagine an Obama attorney general braying, as John Ashcroft did in 2001, that his critics "give ammunition to America's enemies and pause to America's friends."
If Obama loses, though, it may well be because of something he shares with the Bush of 2000 -- a thin political resume that raises doubts about whether he can handle the most demanding job on Earth. If McCain loses, it will be largely because he is identified with the obstinacy and errors of the current White House occupant.
In the end, Americans may vote for either candidate. But after eight years of Bush, most of them will leave the polls singing the words of an old country tune: Thank God and Greyhound you're gone.