If you had stated:
I would probably have responded by stating that in theory I agree with him. The whole notion of "African" American is a bit questionable now, as while historically one could trace linieage there many black people could perhaps claim more European or Carribean blood perhaps than pure "african" blood. Blacks, as well as many whites, could easily be considered "mongrels" in that fashion at this point as the ethnic lineage has became so mixed within the various races and that it'll likely continue to be that way. With the easier its became to travel across the world now it will continually be harder to find "french" people or "african" people or "English" people who are 100% or even 75% of a particular ethnic bloodline.If your purpose is what it CLEARLY was, which was being spurred by Obama's comment and referencing his comment, you could've gone.
That said it's another example of poor judgement on his part using that particular word. While technically it may fit, the word has a definitive negative connotation in the normal and typical usage of it and is just going to invite a potential firestorm. This is akin to suggesting that someone is "queer" because they are odd, while it may technically be true the term is far more often used in modern times as an insult or derogatory way of referencing someone as a homosexual and as such would likely not be the wisest word to use regardless of its technical correctness.
Now, if you ahd stated this
I'd likely state that its multifaceted and would depend on how or why someone was using it. In a very generalized way I'd say its likely meant to be insulting, as the common use and reference to mongrel in most speech today is referencing to rabid dogs or mangy dogs. Thus its either refering to black individuals as savages or something less than human. That said, if using it in its more literal, technical definition it could be something that is considered accurate due to the natural mixed ethnicity that is common today...however if someone was using it only to describe blacks I'd suggest an alterior motive to them since most races at this point in humanity could be considered "mongrels" to a point under that definition.If your purpose was HONESTLY not trying to set a trap and were meaning this in an entirely generalized way you could've gone