Even the deathbed intimacy of the Violas is presented in terms of the strong dominating and silencing the weak.

I believe there is an allegorical shading in the word "graver"; after all, it's slightly surprising that Giorgio should be described as being in any way closer to the "grave" than Teresa. But what he stands for -- the optimistic Libertarian Republic -- is permanently dead as an ideal in the modern world, while Teresa's motif of material betterment will live on in the simmering revolt of the labor classes.