From The Godless Constitution, by Isaac Kramnick and R. Laurence Moore (emphasis is mine):
Yet there is a difference between a Southern Baptist who is inclined to be conservative on many social issues (after all, Baptists have never expected much of the state), and a convention of Southern Baptists who have been lobbied by Baptist leaders to vote for conservative candidates because that is what Christians who read their Bible ought to do. Politics in a secular state means that there is no Christian position on whether tax cuts are a good or a bad idea, on whether the terms of congressmen ought to be limited, and whether the capital gains tax ought to be lowered.There are ways in which Christians are influenced by their religion when they take stands on the question of abortion rights, of whether feeding the poor and homeless ought to be a government responsibility, and of whether the United States ought to support the state of Israel. But that influence leads to different conclusions. None of these conclusions represents the voice of God, not in political debate.