For those of you who are Roman Catholic, I have a long history of commending your church for taking a stance on politicians advocating obviously anti-Christian public policy. In my own theological circles, we need to deal with the fact that our political history during the Reformation was closely intertwined with fights against Roman Catholicism. How can we cooperate with Catholics now when our history was very different?
The core issue is that we now face an even worse enemy — secularism and “enlightenment” thought stemming from the French Revolution. We can work together against a common enemy so long as we realize our differences.
The Dutch church leader Abraham Kuyper, who became the prime minister of the Netherlands a century ago as head of a Christian political party and was the founder of a Christian university, a daily newspaper and a church magazine, and of what became the nation's second-largest Protestant denomination, advocated cooperation with Roman Catholics in the sphere of the state while strongly affirming the need to maintain confessional integrity in the sphere of the church. In the modern context, Francis Schaeffer and D. James Kennedy held very similar positions.
I believe it is entirely consistent to work with Roman Catholics in the political realm to fight abortion and other evils covered by Romans 13. I believe we need to recognize that our confessions will and should keep us from ecclesiastical compromise, but Romans 13 specifies the primary purpose of the state in ways that not only allow but probably require us to work together as evangelical Protestants, traditional Roman Catholics, and Orthodox Jews.
The transgressions of the past are in the past.
"Therefore, if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come." - 2 Corinthians 5:17
We are all called to forgive trespasses, both real and imaginary. If we both concentrate on cooperating with God we will be cooperating with each other. First and foremost we each have to get past the idea that the other is an evil on par with Satan and attack that with is obviously and undeniably evil in our society.
Peace be with you.