Charles Darwin had many Christian friends and allies in his study of natural selection. They saw an easy reconciliation of evolution and faith. Darwin, who was both a fine fellow and a committed atheist, was regularly tied in knots trying to answer questions like this:
Isn't Kermit Gosnell superior to Mother Teresa in an evolutionary sense? He contributed to racial hygiene by weeding out the unfit and unwanted. She nurtured the unfit and unwanted. In the end, a species with 100 Kermit Gosnells will be stronger than one with 100 Mother Teresas.
This was Margaret Sanger's logical extension of Darwinism when she created Planned Parenthood. It wasn't a distortion of his theory, but an application of it.