It is certainly true that we cannot avoid supporting people who do great wickedness, due to the interconnectedness of all things. I think of Paul's statement in 1 Corinthians 5:9-10, "I wrote to you in my letter not to associate with sexually immoral people - not at all meaning the sexually immoral of this world, or the greedy and swindlers, or idolaters, since then you would need to go out of the world." While Paul in the context of these verses stresses the necessity of church discipline for unrepentant sinners within the church community, he acknowledges that the nature of the world is such that we cannot separate ourselves from all evildoers everywhere.
I do not refrain from voting for pro-abortion politicians because I want to avoid moral responsibility for abortion. On the contrary, I already bear responsibility for abortion by virtue of living in a society that practices it. The prophet Isaiah's cry in Isaiah 6:5, "Woe is me! For I am lost; for I am a man of unclean lips, and I dwell in the midst of a people of unclean lips; for my eyes have seen the King, the Lord of hosts," provides a model for my belief in both individual and collective moral responsibility. Isaiah is guilty both for his own actions - being "a man of unclean lips" - and for the actions of the whole nation of which he is part - living "in the midst of a people of unclean lips." It is the same with myself. I agree with the elder monk Zosima in Dostoyevsky's Brothers Karamazov when he says, "For you must know, my dear ones, that each of us is undoubtedly guilty on behalf of all and for all on earth, not only because of the common guilt of the world, but personally, each one of us, for all people and for each person on this earth." This shared guilt binds me to every evil act and every evil actor in humanity. As the burning coal from the altar took away Isaiah's guilt, both individual and collective, so I look to the blood of Jesus shed on the cross as the only thing that can take away my guilt and atone for my sin, both that which I have individually done and that done by those groups to which I belong.
So my decisions on who to vote for are not based on an ultimately futile attempt to avoid the contamination and complicity I already share. Rather, if I am going to vote, I desire to vote for those who will serve the common good, those whose service in a position will benefit the people they are serving. My vote isn't primarily about me, but about society at large. In relation to abortion, I want to vote for someone who is able to conceive of the issue as part of a holistic approach to life, as duckroll rightly commends, as part of seeking to do good especially to those who are neglected and scorned by society, rather than one who is only able to conceive of abortion as a tribal marker. In the situation in which there is no such candidate, I do not see my refraining to vote as inaction, but rather as an alternative course of action - perhaps the wrong action, for I do not claim to possess perfect moral judgement, but action nonetheless. It is my, admittedly meager and feeble, attempt to bear witness to the truth of God, rather than be bound by false binaries asserted by the world. As such, not voting for particular candidates is not merely an isolated, thoughtless lack of action, but part of the whole way in which I seek to live my life, in service to God and others.
