Direct abortions are morally wrong.
The abortion argument is easy to contruct, and sounds fairly universal, but there is an emedded qualifier in the claim. The adjective "direct" allows for interpretation and exception to the rule. In this case, the rebuttal relieves the arguer from having to defend his argument from arguments about the need for abortions in ectopic pregnancies (as well as a couple other exceptions). Rebuttals are good ways to guard against arguments that you have encountered before, or that you anticipate encountering. But there is a danger of allowing so many exceptions to the rule, that the rule itself becomes meaningless.