About 15 years ago I saw this comedy on some cable TV channel. Among others there was a black guy who felt oppressed and dreamed of a time when black people would be powerful. One day some magic happened, he went out in the morning and all position of power were taken by black people. Four black people who used to dig a trench with a white guy watching them, are now watching that white guy digging. Everything turned around. Can you remember that movie?