New research by Burke's Peerage reveals that Mr. Kerry is the only presidential candidate in U.S. history who has genealogical descent from Muslims, Jews and Christians.
Mr. Kerry is kinsman of the Shi'ite shahs of Persia (the most famous was Shah Abbas I, who reigned from 1587 to 1629), as well as the Muslim kings of Tunisia, all of whom � Democratic presidential nominee included � descend from the prophet Muhammad.
I imagine this would be useful to the Jerry Falwell demographic in proving Kerry is the AntiChrist.
 Note that the genetic contribution of a given common ancestor is, of course, completely separate from the issue of lineal descent. As David explains at GNXP,
Of course, it does not follow that all of the �common ancestors� have contributed equally, or even at all, to the genes of all their descendants. At a distance of 100 generations, a single line of descent from a single ancestor would contribute less than 1 part in a billion billion billion to a descendant�s genome. Since there are only of the order of a billion base pairs in the human genome, this means in practice that he would be very unlikely to contribute anything at all. It is only through multiple lines of descent that a remote descendant is likely to inherit anything genetically.
To partially answer Dan's question in comments, Kerry is a direct descendant of the Prophet SAW, whereas Bush is likely only tangentially related to the Prophet SAW by virtue of sharing a common ancestor with Kerry, in much the same way that a pair of cousins have different sets of grandparents. Note that Bush is related to Kerry, they are 9-th order cousins (more info here, and here).