Communism can only hold to their power if there is the only option. It fails once there is competition. Competent people would leave to were their work is valued and they can make a better life for themselves thru the fruits of their labor. You will be left with the ideologs and incompetent to run the system without any motivation to do so. This is why communist nations used to have strict rules about who was allowed to leave the country and you were strongly monitored by neighbors so you would not have bad ideas, like freedom or choice.