Because once it is denied to one person, no one is protected by the law.
Augustus took Julius Caesars place
A spirit of reform marked the Progressive Era from around 1900 to 1917. It was in this spirit that muckrakers, who were influential journalists, worked to reveal injustices and oversights in American society.
Regardless, religion was always the primary trigger for a crusade. Though religion always played a part, the perceived threat to the church evolved. The first Crusade focused solely on ridding the Holy Land of Muslim forces. The popes began to use crusades to combat any perceived threat against the Catholic Church.