Political and judicial authority is binding in conscience only when exercised for the common good, within the limits of the natural moral law.The footnotes refer us to Gaudium et Spes #74 which is printed below:
Even when public authority becomes oppressive, Catholics are bound to obey the laws of the state insofar as they do not conflict with divine law.
But no parliament, no legislature and no court has the authority to set aside the commandments of God, nor to command obedience to laws and regulations that are contrary to the natural moral law.
When this abuse of authority occurs in a democracy, Catholics must take all legal and political steps necessary to defend ourselves and our fellow citizens, and may, in addition, resort to conscientious objection, civil disobedience, non-co-operation and other forms of non-violent resistance in accordance with the natural moral law and the Gospel.
Should such steps become necessary, the unity of Christians and non-Christian believers in God and our willingness to suffer will ultimately overcome the abuse of authority and power of the state.
74. ...It is clear, therefore, that the political community and public authority are founded on human nature and hence belong to the order designed by God, even though the choice of a political regime and the appointment of rulers are left to the free will of citizens.(3)Source.
It follows also that political authority, both in the community as such and in the representative bodies of the state, must always be exercised within the limits of the moral order and directed toward the common good-with a dynamic concept of that good-according to the juridical order legitimately established or due to be established. When authority is so exercised, citizens are bound in conscience to obey.(4) Accordingly, the responsibility, dignity and importance of leaders are indeed clear.
But where citizens are oppressed by a public authority overstepping its competence, they should not protest against those things which are objectively required for the common good; but it is legitimate for them to defend their own rights and the rights of their fellow citizens against the abuse of this authority, while keeping within those limits drawn by the natural law and the Gospels.