I said analogous, not identical. Clearly they see it as bad, but not nearly as bad as murder. If it was literally mass murder to them, I'd expect more bombs and riots, and less "campaign against it for 50 years to repeal it".
If it's "somewhat less than murder" all these states with anti-abortion laws would have carve outs when the mother's life is in danger. You'd definitely allow someone else to commit an evil act that's "less than murder" to save a person's life, wouldn't you?