There can be no doubt that Cain draws on a deep American love of black American culture. Black music, black comedy and black oratory are integral to the cultural mainstream in a way that would have been unimaginable 50 years ago but is now taken for granted. This is no less true of the South, where Cain’s brand of blackness taps into shared religious faith and a love of the region. His manner of speaking only increases his appeal: 9-9-9 is NAN-NAN-NAN. Hill is HEE-oh. Quarter is KAW-tuh.Frank goes on to quote linguist John McWhorter who says that "To be an American person is to hear a certain warmth and honesty and genuineness in black cadence. That’s why Barack Obama was so deft in summoning it, at times."
There are many important differences to note between Obama and Cain, but it's fascinating to also consider that they share a common quality: black rhetorical skills. Sure, their types of rhetorical skills are different, but yet, they are still distinctly black and American skills nonetheless.
Rhetorical skills have been vital to the success or popularity of black men "leaders" in history. Frederick Douglass. Booker T. Washington. Marcus Garvey. King. Malcolm. Then too, look what deft rhetorical skills have done for rappers, a genre dominated by black men, and comedians.
Good oratorical skills are certainly not the only things that explain the widespread appeal of a Cain and the even wider appeal of Obama, but the ability to "move the crowd" so to speak are key assets for both of them.