The novel focuses on social and political power and the way that ambitious people maneuver in order to get closer to the epicenter of this power (themes that are common in many fictional representations of Washington DC, as seen in the musical Hamilton and the TV show The West Wing). The way that this power operates—which begins in "inner circles" and dissipates as it radiates outward—is focused on Washington politics specifically, but can be understood as a facet of power dynamics in general. The nature of it being that it has a ripple effect; an association with such power draws certain kinds of people to its center—the (alleged) best and brightest.

In Democracy, the socially prominent Madeline Lee (formerly Mrs. Lightfoot) finds that the hollow sophistication and refinement of New York City palls on her. Washington society, still very much in development (and even a touch barbaric) beckons her as a place where it's still possible to make your mark. With her sister in tow, Mrs. Lee immediately installs herself as hostess of a salon in Washington, a venue through which she can explore her attraction to power and men of power. She hosts a retinue of eminent, erudite gentlemen—by Washingtonian standards—and a few foreign emissaries (mostly for comic relief).

The most dynamic of these prominent statesmen is Silas P. Ratcliffe, a rising star in the political firmament: his Midwest origins brand him as a Lincoln-esque rustic philosopher. At a private party, Mrs. Lee flatters him over his oratory, and she and the "huge, ponderous, gray-eyed and bald senator" fall into a flirtation, despite their significant age difference. While she and her rapidly growing public meet and greet—exchanging "badinage" and "intellectual somersaults" amongst themselves—this "Favorite Son of Illinois" becomes her focus, as she becomes his.

A number of men have developed romantic attachments to the sisters, but Ratcliffe's attentions generate gossip. Mrs. Lee, herself, has cause to wonder:

The idea [that Mrs. Lee was becoming involved with Ratcliffe] was almost too absurd to be credited. She thought only of his danger, and she felt a sort of compassion for him as she reflected on the possible consequences of a great, absorbing love at this time of life.

The career trajectory of the Honorable Ratcliffe is limitless, as he's being groomed for the Presidency. And the sought-after Mrs. Lee may soon be granted the highest access to power then available to women: the position of First Lady.

Another prominent figure who attends Mrs. Lee's is an Englishman who makes mordant, outsider-looking-in commentary on the nature of Washington politics. As George Bernard Shaw once wrote, it is easier for an outsider to observe the inherent contradictions that people can construct in their "moral gymnasiums." From this outsider perspective, the novel posits a moral question: do the ends always justify their means? Is is better to try to maintain a baseline of integrity, or to simply win?

The novel is itself poised to examine this question, as Adams was intimately aware of the contradictions and hypocrisies that were inherent in the lives and politics of elected statesmen. In this case, he elucidates the problems that statesmen face when trying to represent their constituents. In other words, the:

clash of interests, the interests of forty millions of people and a whole continent, centering at Washington . . . the tremendous forces of government and the machinery of society at work.

Thus, Mrs. Lee must ultimately contend with the question of dealing with the politics of Washington society—whose members range from idealism, to moral relativity, to outright corruption—or with the vacuity of upper-crust Manhattan society.