Because Catholic clergy and laity follow the doctrine of the Catechism of the Catholic Church, which says:
Page 541
Doctrine 2241:
"The more prosperous nations are obliged, to the extent they are able, to welcome the foreignerin search of security and the means of livelihood which he cannot fin in his country of origin. Public authorities should see to it that the natural right is respected that places a guest under protection of those who receive him.
Political authorities, for the sake of the common good for which they are responsible, may make the exercise of the right to immigrate subject to various juridical conditions, especially with regard to the immigrants' duties toward their country of adoption. Immigrants are obliged to respect with gratitude the material land spiritual heritage of the country that receives them, to obey its laws and to assist in carrying out civic burdens.
Doctrine 2242:
The citizen is obliged in conscience not to follow the directives of civil authorities when they are contrary to the demands of the moral order, to the fundamental rights of persons or the teachings of the Gospel.
Refusing obedienceto civil authorities, when their demands are contrary to those of an upright conscience, finds its justification in the distinction between serving God and serving the political community. "Render therefore to Caesar the things that are Caesar's, and to God the things that are God's. (Mt 2:21)
We must obey God rather than men: (Acts 5:29)
When citizens are under the oppression of a public authority which oversteps its competence, they should still not refuse to give or to do what is objectively demanded of them by the common good; but it is legitimate for them to defend their own rights nd those of their fellow citizens against the abuse of this authority within the limits of the natural law and the Law of the Gospel.
Second Vatican Council
This bishop is obeying God and Jesus' Church doctrine.
If by "sheeple" you mean other "obeying in advance" Americans, I can agree.
= new reply since forum marked as read