American Protestant Pastors vs. Americans on “True Islam”

From Ed Stetzer, NEW RESEARCH: How Americans View Islam:

Forty-five percent of 1,000 senior Protestant pastors surveyed say the Islamic State, also known as ISIL or ISIS, "gives a true indication of what an Islamic society looks like." … The pastors had a much darker view of Islam than Americans at large. In contrast, in the second survey, 27% of Americans say the Islamic State reflects the true nature of Islamic society.

Why do Pastors have a much more negative view of “Islam” than typical Americans? I’ve got my theories, but I’d love to hear yours.