Inspired by this question, I'm left wondering how Christians ought to respond to laws that are unjust, but not overtly immoral.
I think most of us will agree that Christians ought to disregard laws that mandate immorality, or that prohibit morality. The cliche examples of the first would be laws requiring turning over Jews to the Nazis to be murdered, or turning over protestants to Catholics to be burned as heretics, etc. And examples of the latter would be laws prohibiting Christian worship.
But what about laws that are viewed as clearly unjust, but don't overtly require immorality or prohibit morality?
Laws such as the one mentioned here that forbade blacks in Pennsylvania from marrying from 1870 until 1973 when the law was changed. Or racial segregation laws like those challenged by Rosa Parks. For a Christian, is civil disobedience an appropriate response to these types of laws?
EDIT
To be clear, I am asking about laws that neither mandate immoral behavior, nor prohibit behavior required by the Bible. In my two examples: A black person remaining single (and celibate) is not immoral, nor does the Bible require anyone (black or otherwise) to marry. Also, it is not immoral for a black person to sit in the back of a bus, nor does the Bible require anyone (black or otherwise) to sit in the front of a bus. So it is quite possible to adhere by both of these laws without violating any Christian principle--and indeed many Christians to this day do live in (unwitting) compliance with both of these laws. Many black Christians in Pennsylvania never marry, and many black Christians ride in the backs of buses.
My phrasing in the title is not intended to imply that I think "unjust" laws are "moral."
A law that prohibits Christianity does not fall into the scope of this question, since the Bible requires that of us. Nor would a law that requires someone to kill or torture another person, since that is prohibited by the Bible.