Vic -- I'll try to research California further later. Sorry about the Oregon faux pas! I get all dem NW states mixed up.
Mark -- I may revisit this thread at another time but I'm going to be travelling for a bit and not able to respond in depth for a while. I'm really not interested another debate on this subject. I don't find debates on the PB to be all that fruitful or edifying (this is not referring to you specifically -- I think you are perhaps the most courteous and respectful poster on the PB) when weighed against the time and energy involved and so debating is not why I am here. My point is merely that public service to a government whether pagan or Christian is lawful and good (WCF 23.2) provided one does not sin in accepting or fulfilling the office (WCF 23.2 also emphasizes the duty to maintain "piety" in one's civic office). The next question is whether entering or fulfilling the office of juror (or other office under consideration) under the provisions of the U.S. Constitution is in fact lawful. The oath involved, btw, does not say anything about "protecting" the Constitution but it does use the word "support." And neither Joseph or Daniel had to swear an unlawful oath to serve in their respective governments, thus showing that one can serve in an ungodly government provided, as you said, "as long as he does not sin directly himself." But beyond that, my participation in this thread will have to wait. God bless, my friend.