In the allegorical progress of Antonia, representing idealism, this is a key moment of historical change. Until now she has been devoted to Don Jose, i.e., idealism has been in the service of nationalism. But now she makes the decision to "rejoin her uncle," meaning idealism will ally itself again with religion. Moreover, she entrusts Don Jose's life to Hernandez, meaning that she has passed the ideal of the nation -- its moral justification and goal -- to socialism. After this change, Antonia will later appear alongside Father Corbelan arguing for national expansion and socialist justice. The implication is that in the modern world, the nation of the material interests no longer inspires idealism; the new ideals reside in a combination of spirituality and socialist ambition, challenging the nation to 'expand.'

Don Jose, as hinted here, does finally die in the woods of Los Hatos. On the physical level, one could say with justice that Antonia kills him by subjecting him to the journey for the sake of a "less debasing" environment, i.e., for the sake of her idealism (note the phrasing, "For herself, her mind was made up"). On the allegorical level, I believe Conrad keeps the old patriot lingering on so that he can die at the moment of Costaguana's actual rivening, which also represents the material interests' triumph over the idea of the sovereign nation. But note that it is only when idealism transfers its support to religion and socialism that the moral voice of nationalism can finally expire.

Observe also the universal attack, encompassing capitalism, implicit in "the irresponsible tyranny of all parties alike." This is an early indication of how socialism will be presented in the rest of Part Three: -- as a protest against "tyranny" as such, i.e., against conquest itself. Hernandez' specific policies are not mentioned here, but the Robin Hood bandit is portrayed as a warrior against "moral darkness."