The Hitler analogy is fatally flawed, because we know why Hitler liked Darwin; he twisted Darwin's findings into something Darwin never suggested - that some races were superior to other races and therefore deserved to rule or exterminate other races as a matter of "survival of the fittest."
We
don't know why Hamas prefers Obama. It could be, as you suggest, because they perceive that Obama would be the best man to broker a genuine peace between Palestinia and Israel, though the evidence that that is what Hamas wants is microscopic, at best. Or it could be because Obama is some kind of secret jihadist mole who will, as president, force Congress to cut off all aid to Israel; the evidence for that is even more microscopic. It could be because they perceive Obama as being weak, inexperienced, naive, or some combination of all three, and they'll be able to take advantage of that. It could be because Obama has been doing some kind of back-channel discussions with Hamas; as Brainster points out, he's done it before with Canada regarding NAFTA, and
one of his Middle East policy advisors got caught having discussions with Hamas (and then dutifully fell on his sword when word got out). Interesting that the story about that advisor doesn't say anything about what he discussed. So what does Hamas know about Obama that the rest of us don't?
You also set up a straw man by saying the position is that "Obama is not a good candidate because Hamas wants him to be president." If you read my posts again, you'll see that I said nothing of the kind. What I said was that Hamas's endorsement should raise questions about why they prefer him.