"Open thy mouth for the dumb in the cause of all such as are appointed to destruction. Open thy mouth, judge righteously, and plead the cause of the poor and needy."
Truthfully, I do not know what to say about these verses. My own thoughts are that we are to make sure that government is just--meaning that everyone gets what they deserve, no matter what other people get. Fairness, in most cases, does not really take care of things. Fairness means that everyone gets the same thing, across the board. I always tell my kids they truly do not want "fairness". If life were fair we'd all live in squalor because millions do, or have cancer because millions do. Life is not fair, nor do we really want it to be.
Also, pleading the cause of the poor and needy: Jesus said if we help even "one of these" we've done it to Him. He obviously holds helping the poor and needy in high regard. Jesus was one to go to the rejects of society and bring them into His fold. He is no respector of persons. We should not be, either.