imagine a scenario where the KKK has acheived such massive popularity that all other alleged forms of Christianity are marginalized or extinct."Imagine"?!? So you mean this *hasn't* happened already...?
(Sorry; bad joke, I guess.)
I suspect that something like this has happened to Islam, and that it happened early on.No no; from all I've read about it, it seems it truly was a tolerant and open-minded culture, once.
In the days of the Caliphate of Cordoba, of Saladin, and of Harun al-Rashid's (of "1,001 Nights" fame; probably a few predecessors / successors of his, too) Caliphate in Baghdad.
Basically, from the ninth to the fourteenth-fifteenth century. Perhaps even longer; lots of Europeans served, apparently not too uncomfortably, under Moslems not only in the early, but almost until the last, days of the Ottoman Empire.
The trouble with these mad mullahs isn't that they want to turn the clock back. It's that they don't want to turn it back far enough.No, it's that they want to turn it back.