They have only voted republican 6 times in history (those by narrow margins), they are following some common ideology, some guiding force.
You should be far more concerned about the GOP deviating from Catholic teaching than the degree that Church teaching can be bent to endorse the GOP.
The GOP platform has varied significantly over the period of time you continue to harp about, yet Church teaching on things like abortion, contraception, same sex marriage, pornography, social justice and access to health-care has remained constant.
"Sir, my concern is not whether God is on our side; my greatest concern is to be on God's side, for God is always right - Abraham Lincoln
Peace be with you.
I'm an independent. No party represents my beliefs as a pro-life conservative Christian.