You frame your reasoning in absurd terms (which is your prerogative). it's like me asking - defend if you know why Palin shouln't deserve her high approval ratings as Governor?
Palin's straight talking appeals to many. Obama has come across as elitist. Many commentators in the UK see straigh away (and even marvel) how Obama can get away with such "vacuous words" (their description).
You apply double standards to your own arguments which you fail to realise: for example - let's face it, Obama chose Biden because that increased his odds of winning too. And if you thought that disqualified McCain, then Obama too is disqualified (by your own "reasoning").
What is the margin of error in your Obama "safe" poll? That sounds rather flimsy. On the other hand real people interviewed on the street have expressed doubt and uncertainty with Obama. Even Obama himself would readily acknowledge that the voters still don't really know him. Hence all that razzmatazz styrofoam decorated stadium for his speech (very eco-unfriendly too, I would have thought!)
Changing positions in itself isn't particularly bad - but Obama changes position - "moving further and further to the right" (as one American journalist has described it) to try and win votes is despicable. Look at his "beyrayal" over FISA. It was pathetic!
"This bill allows the President to grab all incoming and outgoing international communications without a warrant. The ACLU says it represents "an unprecedented extension of governmental surveillance over Americans." Obama, sounding on Friday a lot like Bush
, said: "Given the legitimate threats we face, providing effective intelligence collection tools with appropriate safeguards is too important to delay." [Source: The Progressive - Obama's FISA Betrayal
If you're going to drum up support for Obama, at least be honest!