I think Senator McCain's biggest mistake--the reason he lost the election--was the way he positioned himself. (And by "he" in the following I refer not only to the man but to his campaign organization.)
Perhaps the biggest no-no in a political campaign is to allow oneself to be defined by the opposition. That didn't happen to McCain; he did it to himself.
Seems to me that many people are more influenced by the persona a candidate projects than by the candidate's stands on specific issues or his professed beliefs and values. Even specific deeds, such as McCain's ill-advised selection of his running mate, are more viewed (at least subconsciously) in the larger context of what they reveal about the general character of the man, his overall essence, and less as insights into his decision-making abilities or other specific attributes.
McCain identified himself, repeatedly and with uninhibited relish, as the underdog. I don't think he could have prevented himself from doing so. It's his nature. (Surely some psychoanalyst is working on a book about McCain's psyche and its roots, so I'll leave the scrutiny of his id and ego to the shrinks. They can speculate about the "victim syndrome" and how it relates to his ancestry, his family's early disappointment with him, his imprisonment, and all that other psychobabble rubbish.)
While "everybody loves an underdog" and we may root for them at times, most of us don't really believe that an underdog is the right choice for the "top dog." I think that view is programmed in our genes. (More cud there, with my compliments, for the shrinks to chew on.)
In what ways did he act the underdog?
-- He viciously and unfairly attacked his opponent when he might have stood proudly on his own achievements. He snarled about irrelevancies and yapped at Obama's heels--while the latter stood firm and resolute, composed and presidential.
-- He emphasized trivial, inconsequential chinks in his opponent's armor.
-- He partnered with an insubstantial running mate of trifling accomplishment and minimal intellect, who likewise yipped about petty matters--another underdog who proudly self-identified as something akin to a "pit bull."
-- He introduced us to his friends and most ardent supporters, Joe the Plumber and a mangy gang of rabid hounds, and together they gave the impression of a pack of growling mongrel misfits more suited to a kennel than the White House.
-- He appealed to the insecurities of factions of the electorate: people who feel like underdogs themselves and thought McCain's mongrels were "just like us."
-- He whined about being treated unfairly--a common tactic of frail children who are incapable of defending themselves.
-- He repeatedly raised the specter of the usual bogeymen: higher taxes, socialism, terrorism--rather like a hound barking at the wind in the trees.
-- He charged his opponent with the crime of celebrity--implying that he himself was the antithesis of a superstar, the runt of the litter.
-- He self-consciously lowered himself to a more humble plane than he deserves by constantly addressing the public as "my friends." I don't know whether he did this because of an irritating rhetorical tic or as a desperate ploy to gain acceptance, but either way the habit made him seem pathetic.
But to appear pathetic ("provoking feelings of pity") and feeble was apparently his goal. For he actually TOLD us--on many occasions and most frequently as the contest came down to the final days--that he WAS an underdog, and proud to be one.
And we listened, and we believed him, and we followed the bigger and better-bred dog.