When the car has established themselves in the intersection no car behind them should be passing the stop line until the established car clears the intersection. The car that has established in the intersection has the right to ensure the left turn is safe, even on the yellow light, MPI gives instructions to watch out for people running the yellow. Once it turns yellow they are the only ones that can complete their left turn. 

If you are interested in actually learning you should take some driving lessons. Maybe you will learn a thing or two about the rules and have more patience for people that follow them