The Trouble with Lee Smith...
That didn't stop future Shi'ite dynasties from coming to power. The Fatimids, founders of Cairo, are fairly well-known. Less known are the Buyids from the 10th century, who became the Abbasids' puppermasters during the so-called "Shi'ite century." But even if Smith would bother to check the alleged highlight of his narrative, the martyrdom of Hussein, he'd find it happened in 680, not 656. The latter date was when Uthman was assassinated and Ali, Hussein's father, became caliph. That seems to be a rather blatant error from a supposed Middle East expert.
Then, of course, we get to the really ridiculous stuff, in which the rise of the Shi'ites is related to the emancipation of African-Americans at the time of the civil war. You know, close social and political identification with one's religious group has come about largely as a result of the political environment after the fall of Saddam Hussein - the situation of the Shi'ites in Iraq before that was largely the result of the clan-based nature of political power in the country rather than religious disrcimination.
I'll grant him that Sunni fundamentalists are very anti-Shi'ite, but there really is no grand sectarian Cold War raging in the Arab world. Smith is writing a book on Arab culture. I bet it'll be a wonder to behold.