It's true that a party that was once fine (19th Century), then acceptable (up until McCarthy), then at the least basically sane (until the Moral Majority) has degraded beyond any and all of those, and that evangelical theocrats were greatly responsible for losing the latter two of them. It is however questionable as to whether the much ballyhooed schism of the plutocrats and the theocrats is on the horizon, or even ever going to happen. As the author states, it may even be the reverse.
Christofascists have turned the uneducated plebs' common wisdom against....well....wisdom, or at least knowledge, quite thoroughly over the last four decades or so. It is embarrassing how we rank in questions on such basics as the age of the earth and speciation compared to other industrialized democracies, or even pseudo-democracies. These intentionally stultified gullible troglodytes serve as tabula rasa shock troops for whatever reactionary crap is poured into their heads via the pulpit, and its (vaguely) secularized counterpart of hate radio. Rich people pay too much taxes. Businesses need tax breaks to hire (although all hiring and employee costs are and have long been tax-deductible). Obama is a Muslim. gays are evil. Abortion is murder. Their loyalty to God and their loyalty to party are not in competition at all, but merged in their heads as one and the same.
Facts are no use. Neither is rational argument. Because centuries of apologetics have been built on scriptire expressly warning against human education, learning and knowledge. I'm not sure I can see how to pry God and the GOP apart without an equally massive, equally consistent and equally patient multi-decade push to equate Christianity with liberalism, and I'm not even seeing much of a glimmer of that so far.