Marx on historical materialism

The idea of communism has been greatly understated and defamed by our popular culture. Only by understanding Marx's notion of historical materialism can one have a grasp of when the communist revolution is supposed to take place. Marx talks about capitalist system and how it is built into the system spending money on R&D to make the means of production more and more productive. And a time is going to come when because of all this research and improvement, when supply is going to get ahead of demand. But at this time, there is going to be an imbalance of spending power as the majority of people are simply not going to have money to buy stuff. It is then when the communist revolution is supposed to take place in the form of labor unions coming together. The problem of supply and demand still hasn't been met in the modern world. Thus, any nation trying to become communist is simply acting in futile. It is going to fail.