Satan has a fierce hatred of priests.

Satan has a fierce hatred of priests. He wants to defile them, to make them fall, to pervert them. Why? Because by their whole life they proclaim the truth of the Cross. Priests and consecrated persons cannot leave the world indifferent. They proclaim down to the flesh this truth of the Cross. They will always be a subject of scandal for the world. They take Christ's place. ... Priests and consecrated persons, by their humble, dedicated lives, are a formidable challenge to the power of the world.

[...]

The devil tries to tear the Church apart, first by attacking the priesthood. Satan intends to destroy priests and the teaching of doctrine. He is horrified by the liturgy, the sacraments, and the apostolic succession. In trying to take out his hatred on consecrated persons, he means to ridicule the Church. Priests frighten him because they are the ministers of mercy. He knows that he will be vanquished by mercy. He seeks to instill lukewarmness and doubt in priests. He seeks to win the hearts of some to to draw them ro renounce chastity. Worse yet, he has driven some priests to profane the bodies of children. How can we not see Satan's work in these lives of priests or bishops who have behaved like predators, spreading evil and spiritual death all around them? How can we not see that, in attacking both priests and children at the same time, the demon reveals his hatred of two reflections of God's goodness?

Cardinal Robert Sarah, The Day is Now Far Spent