That’s the core issue with Islam right there.
And people try to argue that this is similar to distrust of Catholics, who were thought to have allegiance to the Pope and not to the USA, which was an issue in JFK’s campaign. This is not even an apples and oranges situation, more like apples and tire rims, completely different. The Catholic Church doesn’t have a doctrine of Jihad and subjugation of the infidel. The Catholic Church isn’t a totalitarian political system with a religious component.
I would also add that there is not conflict of interest for American Catholics. The Catholic Church has not declared war on America.