That poll of U.S. Muslims seems to have included Nation of Islam adherents, most of whom are native American black people with ancestry in this country going back centuries (and the balance almost entirely the children or grandchildren of black West Indian immigrants).
That skews the whole thing, both response-wise and solution-wise. In the matter of responses, N.o.I. is, so far as one can judge from the TV appearances of its spokesmen (I don’t recall seeing any spokeswomen…) just a race-nationalist group with a thin coat of Islam painted over their driving emotions and motivations, which are: hatred of white people. Solution-wise, none of the policies proposed by “separationists”–for example, bribing foreign Muslims to leave the U.S.A., preventing further Muslim immigration–is relevant. Nation of Islam is here, and has no place to go.
The upside, though this is impressionistic, is that N.o.I. types seem to be interested mainly in encouraging black racial solidarity and sounding off about the wickedness of whites, not in “martyrdom operations” (like blowing yourself up in a crowded shopping mall). Giving unpleasant answers to questions asked by pollsters like the Pew Research people, comes under the heading “sounding off” and probably shouldn’t be taken very seriously. Excluding N.o.I. respondents from the poll figures would likely give a clearer picture of the actual danger.