I think both groups can be bad drivers, but for opposite reasons.
First, poor people and immigrants suffer from a lack of training and experience on the road (especially people who grow up overseas or in really poor places where they might not get driver's training in school.) If don't get good driver's training (and if they really are poor, they don't have money to get it on their own, either) they hit the street with the bare minimum and that makes them a danger. Also, they usually buy the cheapest car they can find - i.e. a rolling road hazard- and that further increases the problem. Lastly, because of the expense of operating the vehicle, they probably don't do much more than use it for the basics so they don't really get the kind of practice they need.
Rich people often have the opposite problem. They have so much experience, and spend so much time behind the wheel that they actually have contempt for driving. They try to do everything they can to make the time less about driving and more about what they are missing - thus the cel phones, the coffee pots, the women doing make up etc, etc, etc. The other thing is, rich people feel like they have to be somewhere and try to get through - that makes everyone else on the road and obstacle to either dodge around or roll over.
Both groups are dangerous. Clearly, only I am the best driver on the road.
