To make Marxism work, originally, they used class. They set the lower classes against the upper classes. Obviously, it was just a ruse to get the upper classes replaced with a new upper class who wanted to be in control of everything.

Sadly for the Marxists, the working class were not too keen on joining the revolution so they failed to take over the world.

This time, in the US at least, they just replaced class with race. They are trying their best to set the races against each other to achieve the same end.