Calling those who commit or empower abortion “evil” is not an ad hominem. It is a simple factual statement. And I could care less where a straightforward statement of the truth “chases” them. That is between them and God.
So you're not actually concerned with seeing abortion reduced, just looking good in the eyes of God? That's some arrogance. If you really where concerned about seeing abortion reduced you would care how your statements chase people away. If your actions persuade people that maybe the other side is more rational, how will that help?