My theory is that this is discussing the disgruntled "working class" that exists in pretty much any capitalist society. There's always an upper crust living the good life on the backs of the working class, who get only a tiny piece of the pie as a result. It's saying that eventually these working class will reach their breaking point and start a revolution, and when that happens it will be the ones who had their "shoulder to the plow" who will reign supreme.
My theory is that this is discussing the disgruntled "working class" that exists in pretty much any capitalist society. There's always an upper crust living the good life on the backs of the working class, who get only a tiny piece of the pie as a result. It's saying that eventually these working class will reach their breaking point and start a revolution, and when that happens it will be the ones who had their "shoulder to the plow" who will reign supreme.