Absolutely.
And given the choice between violating the Second Amendment by banning arms or violating the First Amendment by banning the Koran, I know which I would choose.
Islam should not be recognized as a religion. It is a totalitarian socio-political system masquerading as a religion. To ban it under that definition would not be a first amendment violation.
It has to be done carefully, though, to prevent some future tyrant from trying to do the same to Christianity, Judaism, Buddhism, etc.