To imply that it is common for pro-lifers to get abortions is an outright lie, but when it does happen it simply reinforces the pro-life position.  If even people who know abortion is murder will, if given the right pressure, submit to it, then it becomes even more obvious that unborn children must have their lives protected by law.  Further, to suggest that the pro-choice position is justified because a few pro-lifers have taken their daughters for abortions, is as illogical as saying rape is justified because some police officers have committed rape.