I’ve been reading Sean Hannity’s book Deliver Us From Evil. I’d recommend it to liberals and conservatives and everyone in between (even though it is from a mostly conservative viewpoint). It gives an interesting perspective on America and gets you thinking. It’s also written very eloquently so it’s a thoughtful read.
Anyway, I thought this exerpt was very poignant:

Today’s moral relativism is clearly out of step with the traditions of our nation, as the Framers’ own words reveal. The foundations of our country recognized the presence of evil in the world and in human nature, and arranged the structure of the government under the Constitution to protect against its ill effects. As James Madison, the father of our Constitution, reveals in Federalist Paper No. 51, the matter of evil was very much on the Framers’ minds as they debated the form and nature of the new government.
“If men were angels,” Madison wrote, “no government would be necessary. If angels were to govern men, neither external nor internal controls on government would be necessary. In framing a government which is to be administered by men over men, the great difficulty lies in this: you must first enable the government to control the governed; and in the next place oblige it to control itself.”
Madison’s point is especially trenchant today, though the voices of the left might well deny it. Unlike our Framers, modern liberals tend to see government as the grantor of our rights. Uncomfortable with the idea of God-given natural rights, they seek to substitute their own concepts of liberty and justice — whatever they may happen to be in the moment. They prefer the idea of a “living and breathing” Constitution, one that can “change with the times.” Yet what they fail to see is exactly what Madison warned against: that a government with unchecked power — whose authority is not grounded in a more fundamental source of morality — leaves its people unprotected from evil.