I would posit that any group of human beings is capable of embracing the violent social patterns and reactionary ideation that undergirds fascism under the right circumstances: strong group identity, commonly perceived external threat, conformist thinking, and access to some form of structural, material, social, and/or political power/privilege.
If you mix those key components into a group setting, bad things can and will happen.
New Atheism was a microcosm of a much larger human pattern.