When are militia Christianist (not Christian)?

Andrew Sullivan is a gay Catholic who gently suggests:

Surely we can all assent to the notion that a Christian militia of the type now accused of planning domestic terrorism is not Christian. This is why I call them Christianist. Anyone planning to murder innocents by way of IEDs cannot plausibly call himself or herself a follower of Jesus of Nazareth.

To which Skeptic PZ Myers replied at some easy-to-read length, asserting that there are Christians (the real thing). And Christianists, a term William Safire traced back to Andrew Sullivan, who on June 1, 2003, wrote:

I have a new term for those on the fringes of the religious right who have used the Gospels to perpetuate their own aspirations for power, control and oppression: Christianists. They are as anathema to true Christians as the Islamists are to true Islam."

.

No friend of matters mystical, Myers of course fences almost everyone we know up with Christianists, but that's a part of what he does. Whereas most of us may seriously entertain the possibility that the Hutaree are Christianists. And we are not.