The loyalty to the constitution is not absolute either. When it speaks to how the elections are held, taxes levied, public works funded and wars declared, the loyalty belongs to the constitution. When the constitution is used to discover a right of a mother to kill her unborn child, or for two (or more) perverts to "marry", or forbids prayer or religious monuments, or to command pharmacists to sell contraception, then these laws, no matter how much they ostensibly rely on the constitution, do not have to be obeyed. If we obey them, that is not out of civic obligation but to avoid some greater harm.
From the words of Pope Leo XIII.. “if laws of men contain injunctions contrary to the eternal law of God, it is right not to obey them.. “