Part four opens with an extended description of French politics in the years 1830-1832, much of it focused on King Louis-Phillipe and the July Revolution that installed him as (to hear Hugo tell it) a compromise candidate between people who wanted a king and people who wanted a leader who wouldn’t infringe too much on people’s rights. Naturally, no one’s quite satisfied with the results, leading to an ongoing, simmering unrest below the surface.
Despite the specifics to the July Monarchy, there are a lot of universal issues: political philosophy breaking into factions, solving both the production and distribution of wealth (Hugo disparages both communists and unrestricted capitalism on the same page), etc. “At times the conscience of the honest man caught its breath, so great was the unrest in the air, with fallacies and truths intermingled.” That sounds sadly familiar.
It does eventually get back to the ABC Society, and their efforts to maintain ties with various groups of people in the city. Grantaire, trying to impress Enjolras, insists he’s perfectly capable of both walking to the quarry to meet with the marble workers (his shoes are capable too!) and talking revolution with them. I know stuff!
Naturally he ends up playing literal dominoes instead of setting up figurative ones.