So Palin is likeable because she is not the same sex as Hitler, not a war hero like McCain or Hitler, and didn't lose her father early in life like Hitler?

Absolutely,
Yes !
If similarity to Hitler matters at all, then differences from Hitler also matter , and in a matrix of Hitlerness vs Mother Theresaness , Sara Palin scores many more points of closeness to Mother Theresa than all of the other candidates.
Since Hitler was a Vegetarian , her Moose shooting carnivorous nature matter.
Since Hitler wrote a book about his life , McCain suffers this similarity once and Obama twice , this matters a lot.
Hitler was charming and gave a good well rehearsed speech to enthralled crowds , OK so Biden does best in this category by putting enthusiastic audiences to sleep.Hitlers Charisma was legendary , so the most charming canadate suffers most from this comparison .Hitler was a change canadate just like all of our canadates this year.
But Femaleness matters most of all both because it is both a difference from Hitler and a similarity to Mother Theresa. Females as we all know are dependably less warlike and more compassionate than any of us stuck on the Hitler side of the gender equation.