trailer blood

Typically someone who would be considered "ghetto," "trashy," or "ignorant." It insinuates that someone who is undesired due to the way they act or what they say, has trailer blood in them. That they are basically "trailer trash." It doesn't necessarily make them bad people, they just aren't that bright. It kinda goes with the line, "you can take the girl out of the trailer park, but you can't take the trailer park out of the girl."