That's actually a matter of intense debate with the druse and Beduin communities.
Butler also seems to say that the non-Jewish population consists of three groups: Palestinians, druse and Beduin.
At the same time, Butler's comment defines druse and Beduin as not being Palestinian.
member of a Muslim sect centered in Lebanon, 1786, from Arabic duruz, plural of darazi, from name of the sect founder, Ismail ad-Darazi (11c.), literally "Ismail the Tailor."
n. pl. dru·sen (drōō'zən)
One of the small hyaline or colloid bodies sometimes occurring behind the retina of the eye.