Help with physics of dolly turning

Thanks for those replies. I can visualize the pan turning the opposite direction at first, because of the tail swing. Then, in a constant radius turn, it seems like the pan's angle would have to turn the same angle as a car's wheels in the same radius turn. I understand the pivot at the hitch, but if you pulled the loaded dolly around a turn (if somebody was strong enough) doesn't it seem like the swiveling angle would limit the amount of turn? Since I've hit the stops for sure, what is 'giving' that allowed those turns to be made? I'd like to understand the physics to see where the stress goes.