Did you really just say that? So 100% of KKK members engage in violence in pursuit of their ideology? WTF do you take me for?

The KKK members that are constrained by the criminal justice system cannot express their violent intentions, just as those sharing the same views as jihadis cannot all express their intentions through acts of terrorism. But to say that there are no members of the KKK who are fundamentally non-violent is as silly as saying that there are those who consider themselves allies of the contemporary jihadi movement are fundamentally non-violent. A KKK member in shackles is still ideologically committed to violence even though they cannot express that violence. I am not committed to a violent ideology, and wouldn't be violent whether shackled or not. That is the case for Muslims who do not share the jihadi ideology.

because where the KKK diverges greatly from mainstream christian beliefs, radical islamists do not diverge from mainstream islam, they in fact follow the faith to the letter

KKK members also believe they follow Christian doctrine to the letter. They simply have a different interpretation of scripture than the Southern Baptists, for example. They both appeal to the same book. They simply interpret certain parts differently and focus on different passages for justification for their beliefs and actions.

The KKK is a racially motivated group. The fact that they're christians is incidental. Islam is on the other hand is central to islamism.

Both Christianity and Islam are big enough to contain radical and politically dangerous elements. Both the KKK and jihadis justify their actions and beliefs through their scriptures. Christianity is a central element to the KKK as Islam is to the jihadis. There is plenty in the bible to justify violently racist beliefs and actions, just as there is plenty in the koran to justify violently ideological beliefs and actions. The KKK demonizes the non-whites while the jihadis demonize the non-believer. Both do it according to their interpretation of their scripture, along with their political, social, philosophical, etc., beliefs. We can identify causes that effect the actions of Klansmen and Jihadis outside and within their religious foundations. I think the most meaningful factor for both would be sociological and political. Though, perhaps there would be some who could point to economic or historical factors with more analytical success.