Well evangelicals got the Republican party where they are. If they don't want us, since we seem to be deemed to revolutionary I would not mind forming our own group.
My guess is what would happen is that the Republicans would no longer be elected to national offices which would go to Democrats, so the Republicans would be forced to either form a coalition or be relegated to the "whig" ash heap of history.
how many elections would your Jesus party win?
In fact, I think some day Christians might want to form their own society, separating themselves from the godless secularists that have so screwed up our country. Look for great numbers of genuine Christians wishing to bring up their children in a God-pleasing environment instead of one run by Satan's followers. It could be done if evangelical pastors will take the lead.