It's the same garbage that causes them to be always fighting a losing battle.  "Unborn baby can feel pain."  OK, so you eliminate the pain with some anesthetics (legislate a method of abortion that's painless for the unborn baby), or use a morning-after pill (before the baby's nervous system has developed), and now you're balancing this now-non-painful procedure against the "pain" and "suffering" of the poor young lady (99% of whom were victims of rape and incest).

They're not fighting on the principles and so they'll never "win".

Ah, they'll say, it's just tactical, and we'll fight one battle at a time.  But they're fighting the "battle" in such a way as to set themselves up to lose the war.  "Oh, OK.  We agree.  Let's put in some federal legislation to require certain abortion methods and procedures that do not inflict pain on the unborn baby."  Game over.  Congratulations.  You've won the "pain" battle but lost the Pro Life war, since you gave up on the principles.