shes a turnip I believe the Nazis referred to jews as untermunshen (SP) which means subhuman. Before you can kill someone, you first have to dehumanize them. That's the essence of Roe v. Wade as well (just blobs of unhuman tissue with arms, legs and a brain). Obviously, a turnip is not human.
Untermenschen -- Yes, "subhuman," anyone who wasn't of the Aryan Master Race, not just Jews. And yes, that's the thing of it, you've got to represent your intended victim as either less than human, or evil, or both. Otherwise, people will be people and will resist violations of moral law towards each other. Once you get them to hate -- then they are slaves and you can get them to commit the most heinous offenses. Once they hate, they will build Auschwitz.
To say "Terri's a turnip," or "in a PVS," or any such formulation is preparation for doing evil.