The more conventional theory relates to the tea party, which was flaring up around this time. Instead of incorporating tea party into platform, GOP attempted to satisfy/retain tea party voters with a meaningless VP pick.
That theory also aligns with why Hussein got the Dem spot; the anger and sense of disenfranchisement of the tea party was not limited to right leaning folks, and Dems thought HRC was too establishment for the mood of the country. Enter a young radical, and well, you know the rest.