It's been a few years since the coup when the novel begins. Eugene has risen to a position of great influence with Emperor Napoleon III but has recently fallen from grace. He waits for an opportunity to make his way back into favor. He gets his chance when he hears of what amounts to a terrorist plot against the Emperor. He keeps the information to himself rather than warning anyone and, once the plot comes off, the Emperor's anger and fear provide an opportunity for hardliner Rougon to come back to prominence as Minister of the Interior. Amazingly resonant for post-911 America!
Rougon's use of his power once he is back in favor is largely to benefit his close friends with favors and position. He does little or nothing for the people or the country and actively curtails freedom of the press, authorizes groundless arrests, maintains a spy network, etc.
I'm finding that each of Zola's novel in the Cycle focus not only on a different member of the Rougon-Macquart family but also on a different facet of society (e.g., the art scene, urban poor, the theatre, business, etc.). His Excellency, Eugene Rougon tackles politics, and the character of Eugene Rougon is someone who covets political power of any kind. He likes the feel of power and the way people treat him when he has it, but he has no particular aspirations for using his power in any truly constructive way. He wants it the way a sewer rat covets a shiny object.
The key scene is towards the end of the novel where a charitable event has the main characters buying and selling things from each other for exorbitant prices, while one character mans a 'lucky-wheel' that keeps spinning as people step up to pay for 'a try'. It's the perfect metaphor for venal politics, and the overall impression is that politics is a game where players gain their influence for private profit with no thought at all for the public good or the country. Once again, Zola's biting social satire feels all too relevant for modern day America.
While the political satire in bitingly on target, His Excellency, Eugene Rougon is not as well plotted as other Rougon-Macquart novels. The realism of Eugene's inertia and the way he just sits around waiting for the political tide to change doesn't make for a compelling story no matter how much truth resonates in it. Even his downfall, rise, downfall, and rise do not help much. It's not as though he's orchestrating efforts to get back into power or falling from grace in some form of justice or karma. It's just the 'lucky-wheel' of politics turning.
As in all the Rougon-Macquart novels, the outlook is extraordinarily cynical and pessimistic. The realism of the novel, however, prevents you from dismissing what is presented. It's too credible, too familiar, and all too likely to be true. Bottom line, His Excellency, Eugene Rougon is interesting as an element of the Cycle but is not especially successful as a novel on its own merits. This may be why the only translation remains the Vizetelly translation, which is readable but has had some of its more shocking aspects unfortunately 'cleaned-up'. Read this one only if you're out to read all twenty novels.