By that logic, any law promulgated by any political authority, is valid, and should be obeyed without question.
Thomas is upset (and rightly so, I'd imagine) because circumstances are threatening so force him to choose between his practical respect for the law and the tenets of his belief system. It's the same thing I'd imagine has been giving Jeb Bush fits these past few weeks. No one really wants to face the contradiction, because it means an end to a way of life that required nothing of us.
A fair reading of Romans 12 & 13 confirms this as well. We are to follow God's law, "love one another" - "Be not conformed to this world, " etc. And yet, we are commanded to respect the social insitutions, to render tribute, custom, fear and honor where they are due.