The KKK was an avowed Christian protestant movement, so that accounted for anti-"papist" bigotry. That still existed among non-KKK protestants in the North, in my childhood. Anti-Jewish prejudice is still widespread throughout the US, including among self-described Christians. Many if not most of our home-grown religious bigots (I didn't mention the KKK, YOU did) are self-described Christians. But that's the point. Certainly there are a lot of Muslims who are religiously bigoted, but there are far more that are not, witness the 1500 years of religious tolerance toward Christians, Zoroastrians, Yazidis, Jews, and others in the Middle East until the twentieth century.

My comment specified the religious intolerance of MILITANT Islamists, who I compared to US  bigots (without mentioning the KKK) (I didn't call them religious bigots). You are the one who brought in the topic of religious bigotry in the US, while I was talking about mostly racial, ethnic, and sexual bigotry, not the KKK.