And that makes no sense.
The Native Americans accepted the 'refugee' Pilgrims, and look what happened. So this 'joke' implies that if we let refugees in, they will pillage our land and eventually take over (which I don't think is the point that the refugee supporters are trying to prove...).
So no matter what side of the issue you're on (or stuck somewhere in the middle like me), this image does not prove your point. And this issue is not a joke.