A brief thought about politics and faith

"Political appeals, even if rooted in religious convictions, must be argued on moral grounds rather than as sectarian religious demands -- so that the people (citizens), whether religious or not, may have the capacity to hear and respond. Religious convictions must be translated into moral arguments, which must win the political debate if they are to be implemented. Religious people don't get to win just because they are religious. They, like any other citizens, have to convince their fellow citizens that what they propose is best for the common good -- for all of us, not just for the religious...Christians should offer their best moral compass to the nation but then engage in the kind of democratic dialogue that religious pluralism demands."
--excerpt from blog post on "God's Politics" by Jim Wallis

I have been unsure for quite a while as to how to vote/lobby politically for issues that I am passionate about (and those that I'm not but that force me to make a choice). I'm told church and state must be separate, but I can't separate my spirituality from my perspectives on justice, politics, and morality that influence how I vote. But I'm also hesitant on some issues to vote a particular way just because I think it's wrong; sometimes I think that the law should allow for a broader course of action based on a more general consensus among the people it governs. After all, I don't want the law to regulate what I can wear, for instance, just because someone else thinks a particular style is indecent. And vice versa. Just because I think something is harmful or wrong doesn't necessarily mean I should vote that way.
But...sometimes it does. Like when things like justice and life and quality of life are on the line--but how to untangle the messy roots of a particular issue to figure out how to vote justly on it? And accommodating the larger society is not always ok because of things such as institutional racism, blinding nationalism, oppression of immigrants, etc. Just because there's a more general consensus to participate in such things does not mean that I should vote to allow them through law!
So basically, I'm still confused. But I thought the above quote was interesting to reflect on in the midst of my confusion.