Even if you're opposed to abortion, or have negative views about the historical legacy of Dr. King, this isn't the right way to argue. If you call Fiona a _murderer_, that causes me to form a whole bunch of implicit probabilistic expectations on the basis of what the typical "murder" is like—expectations about Fiona's moral character, about the suffering of a victim whose hopes and dreams were cut short, about Fiona's relationship with the law, _&c._—most of which get violated when you reveal that the murder victim was an embryo.
Even if you're opposed to abortion, or have negative views about the historical legacy of Dr. King, this isn't the right way to argue. If you call Fiona a _murderer_, that causes me to form a whole bunch of implicit probabilistic expectations on the basis of what the typical "murder" is like—expectations about Fiona's moral character, about the suffering of a victim whose hopes and dreams were cut short, about Fiona's relationship with the law, _&c._—most of which get violated when you reveal that the murder victim was an embryo.