It is not the case that Americans are more frightened of Muslims than being slaughtered. But they are more frightened of Isis terrorism than the risk of being slaughtered by lone nutters etc. The reason is that the Isis terrorism potentially threatens all Americans since it is an ideological organised terrorism rather than random lone attacks by unorganised nutters.
Labour's Shadow Foreign Secretary, Hilary Benn, said the following about Isis terrorism in what was called his "historic speech" in Parliament
"And we are here faced by fascists," he said.
"Not just their calculated brutality but their belief that they are superior to every single one of us in this Chamber tonight and all of the people that we represent.
"They hold us in contempt.
"They hold our values in contempt.
"They hold our belief in tolerance and decency in contempt.
"They hold our democracy, the means by which we will make our decision tonight, in contempt."
People are frightened by that.