I just posted a review of a book I read. I'm into studying the intersection of politics and religion, and this book, Carl Trueman's Republocrat: Confessions of a Liberal Conservative, asks some of the same questions I've been wrestling with for the past several (probably about 8 or so) years. I'm actually about two years late on the book--it came out in 2010.
Trueman is a professor of church history at Westminster Theological Seminary, hardly a Marxist, New Left, or theologically liberal institution, but he does bring up some very important questions regarding the seeming inconsistencies in the current religious right's thinking. Theologically, he is not a liberal; politically, he is not a conservative (although he opposes abortion and gay marriage quite vociferously at times in the book).
I would urge anybody with an interest in the intersection between Christianity and American politics to read the book. The book will probably cause some people angst (actually, on both sides), but it's a discussion that I think needs to be held, especially for those who believe that Christ and the gospel is above every political system. I don't agree with everything Trueman says in the book, but it is quite humorous and an easy read (from a readability standpoint, anyway). I read the whole book word-for-word in under three hours. I highly recommend it.