I just cringe when someone misinterprets the "establishment clause" of United States constitution to support their religious agenda. That clause precisely means that the government can't establish a church or restrict the free exercise thereof. That doesn't mean that the church doesn't have to abide by the laws established by Congress or else polygamy would still be legal. Churches still have to abide by labor, health and safety laws.
I can keep my politics secular, but I know many don't and I don't really have a problem with that. It's when Christians forget that the constitution belongs to everyone, not just Christians. Some believe that we should be governing, using what they interpret to be Christian principles but that's not my interpretation, of “we the people."
As it is, religion only comes up as a social issue and mostly by one political party. There are some groups that can't simply “agree to disagree" on the issues like abortion and gay marriage. They set up a wall of separation (either you are for me or against me), and their Biblical principles will not be compromised. Their mission, no matter how they try to camouflage it, is to overturn Roe v. Wade and established a constitutional amendment to ban gay marriage.
There are also groups like the Family Leader who have called on the presidential candidates to sign a pledge supporting their interpretation of "family values." According to their guide, a strong Christian leader understands the key elements of "God's law." Those Christian leaders have to be for smaller government, an ethical free-market system, and understand the right to bear and keep arms for defensive purposes. If asked, I'm sure they'll interpret the constitution for the candidates. I'm pretty sure the Republican politicians signed the pledge thinking that it's just the cost of doing business because there's no penalty for not adhering to the pledge.
As I've told a poster several years ago, I will not have anyone defining morality to me. I think everyone having comprehensive health care, a decent wage and benefits, clean air and water and being good stewards of the earth are moral issues. I think the life in -between is just as important as the beginning and the end of life. I can't remember reading a letter where a Christian had a legitimate concern for the poor, the uneducated, the disabled, or the environment. I might add that some must not believe that “bearing false witness" is a moral value because they don't do a lot of research before posting. Yes, there are different opinions but a good researcher knows both sides of the argument.
We all know that we have more than a single issue to worry about, but as I say every four years, the next president will likely pick one or two Supreme Court judges, and that will set the agenda for the future. If you believe that there is not a litmus test for a Supreme Court judge, then you are pretty naive.
In case you are interested,I could vote for a non Christian or a different sexual preference but I know they wouldn't have a chance to be nominated;not in my lifetime anyway.