I have been an admirer of Ron Sider, President of Evangelicals for Social Action (ESA), for years. He is perhaps the most thoughtful and insightful evangelical leaders of political thought. Among is many books include Rich Christians in an Age of Hunger: Moving from Affluence to Generosity, The Scandal of Evangelical Politics: Why Are Christians Missing the Chance to Really Change the World?, The Scandal of the Evangelical Conscience: Why Are Christians Living Just Like the Rest of the World?, and Good News and Good Works: A Theology for the Whole Gospel.
In this article from PRISM (the magazine from ESA), Sider gives some great insights into the candidates on many of the issues that should concern evangelicals in this election.
McCain or Obama? (pdf)