Unfortunately, the barbarous antics we witness today are also Moslem. To that extent Ted Cruz is right. The reason we can say that is because its really nothing new and it continous to have influence today outside of Syria. In the 13th century the House of Saud aligned itself with Wahabism and thats what allowed it to consolidate its hold on the Arabian peninsula. That partnership is still very much in place.
Its also true that Moslems as conquerors, Arabs and Turks, have been much more tolerant of non-believer minorities than Christians. At the time of the real Caliphate they were also at the helm of one of the most powerful civilizing influences in human history. Arab moslems were commenting authoritatively on the works of Aristotle when Europeans were living in caves.