Where does "Obama's Baby Mama" have any racial suggestion in it? I will do my best.
Obama - Barack Obama, a person
Baby - In this context it means Obama's child/baby.
Mama - In this context it means the mother of Obama's baby.
So from, "Obama's baby mama" I come up with the Mother of Obama's child. It may of not been professional, but I don't see where race comes into this.