Mercer Professor and renowned Baptist ethicist David Gushee has a very important piece on the ethics of evangelical engagement in politics today. These seem to me to be the most important points:
"If there are people who reject God or the church, Christianity or religiously inspired moral values because of what conservative evangelical political activists do, this is disastrous from a Christian point of view."
"Once any group of Christians gives itself away so completely to a political party, it ceases to be the church."
"The fundamental task of a religious organization is to serve God, not win in secular politics."
Amen and amen.