Let's see what the original AH Dictionary definition is...
[blockquote]"
anchor baby n. A child born to a noncitizen mother in a country that grants automatic citizenship to children born on its soil, especially such a child born to parents seeking to secure eventual citizenship for themselves and often other members of their family."[/blockquote]
What is unfactual about that? That
is the definition. Adding the "derogatory" tag will not change the fact. It will make the definition
less factual, and subject to opinion. That is not the job of a dictionary.