Mr. Obama said he looked forward to the day “. . . when Jerusalem is a secure and lasting home for Jews and Christians and Muslims, and a place for all of the children of Abraham to mingle peacefully together as in the story of Isra, when Moses, Jesus and Muhammad (peace be upon them) joined in prayer.” Now, the term “peace be upon them” is invoked by Muslims as a way of blessing deceased holy men. According to Islam, that is what all three were - dead prophets. Of course, for Christians, Jesus is the living and immortal Son of God.
But Jesus really is a holy man in Islam! He's regarded as one of the prophets, and a significant one at that. Jews and Christians are, according to Muslim sacred texts, the "people of the book" and receive some recognition and appreciation for believing in precursor beliefs instead of full-on Islam. Admittedly, history has hijacked that special status to some degree, but it is based on what these folks actually believe.
Gaffney has become the beachhead for the "Obama's secretly a Muslim" conspiracy theories. If he wants to convince anyone else, he's going to have to do a lot better than this. Occam's Razor would explain this sort of thing as Weigel does, which is that Obama is merely using local and religious jargon in an attempt to reach his audience. This isn't exactly an obscure rhetorical device--I remember it well from SCOM 101 back in college. All conspiracy theories ultimately fail the Occam's Razor test, which is basically to say that there are always simpler explanations for the facts. Of course, if one is obsessed with the idea that the President is secretly a Muslim--why that would matter in the first place is still a mystery to me, as few Muslims are al-Qaeda--one will find evidence of that in otherwise innocuous-seeming places.