In his comment, Jeremy Pierce, aka Parableman, used a phrase that I've heard often from evangelicals: "vote their conscience." You could substitute this with "vote according to their values," and mean pretty much the same thing, so that's how I'm going to talk about it from this point on. More often than not, this sort of phrase is used in a fashion similar to the following:
Evangelicals should vote according to their values, and should not be faulted for doing so.The first time I heard a statement like this one, my initial reaction was one of complete agreement. Obviously, in a democracy, people should vote how they want to, and more often than not, they will want to vote according to their values. But then I started to think about it. Can people always vote according to their values? Might their be some circumstances in which doing so will lead to contradictions? In particular, are there not some groups of values that, as guides of personal behavior, are perfectly consistent, but, when they determine public policy decisions, can contradict each other? If this is the case, then people should not always vote according to their all of their values, and when they vote according to some values, they should be faulted for doing so.
To make this all more clear, consider an example of a value that is shared by many, if not most Americans, regardless of religion. I think it is safe to say that most of us place a great deal of value on our religious freedom. Furthermore, I think the concept of religious freedom that most Americans hold contains two components, either explicitly or implicitly. The first component, call it the positive component, holds that we should have the freedom to practice the religion that we choose, in the way that we choose (within reason, of course). The second component, call it the negative component, holds that we should not be forced by law to practice any part of other peoples' religions. The positive component simply says that if I want to be a Southern Baptist, I can be, and I should be able to perform the behaviors that my Southern Baptist faith prescribes. The negative component says that if I'm a Southern Baptist, I shouldn't be forced by law to go to confession, or pray to Mecca 5 times a day, or eat only kosher foods.
Assuming that most Americans value both of these components of their religious freedom, and value them highly, it stands to reason that there are some religious values that individual Americans have, but which should not guide their voting. For instance, Muslim Americans who share this value should not vote to force all women to wear Burkhas in public (or vote for politicians because they support laws of that sort), because it is inconsistent with the negative component of religious freedom. On the other hand, there are values that are primarily or entirely religious (e.g., anti-abortion values) which, though they are religiously-motivated values, can reasonably be said to trump the value of religious freedom. I suspect that most Americans who believe that abortion is murder feel that life is more sacred than absolute religious freedom*. So, in the case of burkhas, one probably should not vote according to one's specific religious value, but according to one's broader belief in religious freedom, while in the case of abortion, one should probably vote according to the specific religious value even if it conflicts with one's concept of religious freedom.
The question individuals have to ask themselves, then, is which religious values should and should not guide voting, given their belief in the the two components of religious freedom above? Which are more like the burkha issue, and which are more like abortion? There just happens to be an excellent example in contemporary American politics that can illustrate the difficulty in answering this problem: gay marriage. I, and many other secularists or liberal Christians are likely to feel that opposition to gay marriage, which is almost always motivated by religious beliefs, should not guide voting. When it does, it violates the negative aspect of religious freedom in a way that is more like the burkha example than the abortion one. Many conservative Christians may think otherwise. They may believe that the case of gay marriage is more similar to abortion than to burkhas.
The long of the short of all this is that the statement, "people should vote according to their values" is too broad, and in each case, we should look at the particular set of relevant values before determining which ones should guide our votes. The second lesson is that people can, and sometimes should be criticized for voting according to certain values, but it's likely that many of us will disagree about which cases deserve criticism, and which do not. Thus, the real lesson is that justifying one's vote by saying ,"I am just voting my conscience," or, "I'm just voting according to values," is just another way of saying, "You and I disagree." Furthermore, such appeals carry no more weight against criticism than mere disagreement, which is to say, none at all.
* Before anyone starts to wonder, I am vehemently pro-choice, and in this paragraph, I am simply trying to articulate what many anti-choice Christians may believe.