How do I know? Same way the doomsayers do -- a Mayan says so.
Many an ethnic group can find itself canonized as a source of ancient wisdom and/or down-to-earth good sense. The ``magical Negro'' has his own Wikipedia entry. Magic Asians are a staple of martial arts movies and certain political causes.
I think there is also such a thing as a ``magical Caucasian,'' and that you will find him in the writings of many British authors, including Stevenson, Kipling, Shaw, and T.E. Lawrence.
The Magical Caucasian studied at Oxford or Cambridge, can learn to fly a helicopter or cure dengue fever in five minutes, and speaks all necessary languages. He is omnicompetent and wise, and he floats above the petty concerns of other white people, while understanding non-whites in all things. (Stevenson, Shaw and Kipling had the Magical Caucasian drop down at important junctures to straighten out lesser mortals. Lawrence of Arabia, meanwhile, tried to be the Magical Caucasian himself.)
Point is, the Magical Caucasian has all the imperial virtues (knowledge, good intentions, power) with none of the imperial nasties (racism, narrow self-interest, cruelty, etc). So he is as much a comforting fantasy for white people as the Magicals Negro and Asian.
One of that icon's descendants is today's Magical Maya, the Amerindian who knows when the world is cooked. Unless you prefer the one who explains that the ancient Mayans just marked 2012 as the end of a cycle and didn't get around the carving a new calendar. Which means believers are the equivalent of a kid who thinks there is no next year because his parents haven't bought a desk calendar for 2010 yet.
Magical Ethnies are a fascinating fantasy -- they are a way of consoling ourselves for our obvious ignorance, inadequacy and confusion. Rather than accepting that no one has a clue, it's much more appealing to imagine that the key is lying in someone else's attic.