This is the third in a series of posts between myself and Jennifer Howard about Henry Adams’ 1880 novel, Democracy. Read her first post.
Your point about Madeleine’s transgression is right, and, yes, a little chilling: Her mistake isn’t so much getting stuck between two romantic rivals, Ratcliffe and Carrington, but within the politics that drive the competition between them in the first place. Like you, I can try read Democracy as a romance, but recognize that doing so only goes so far because—as you point out, Adams can be so black-hearted. Maybe he’s set the tone for the serious novel about Washington politics, which has to strip itself of optimism lest you come off as a Pollyanna. I’m reading Thomas Mallon‘s forthcoming Watergate—a novel that owes a lot to Democracy, I think, and which also reminded me of the imposing statue that Adams commissioned for his wife’s grave marker. It’s jet black, scoured clean of anything that suggests redemption, and evokes bottomless grief. And yet, when ever I wind up in the Smithsonian American Art Museum, I always make a point to visit the replica there. That’s just the kind of person he was.
So while I want to be reassuring and say that there are points where Adams wants to give democracy a chance, I don’t think his heart was ever in it—there’s no silver lining he can’t find a storm cloud in. But I’ve wondered, perhaps like you, why I found the novel so enjoyable in spite of all that, because I wouldn’t enjoy a novel that simply took whacks at D.C., however cleverly.
I think a couple of things are at play—aside from Adams’ quick wit, which I mentioned in my first post about the book. Adams can also brandish what I suppose you might call slow wit, a way of setting a scene that captures both its beauty and it complexity. Think of the virtuoso opening paragraph of chapter six, when we finally escape the airless gloom of D.C. and head down the Potomac to Mount Vernon. The passage shifts from charming and pastoral—“one is conscious of walking in an atmosphere that is warm, palpable, radiant with possibilities.” Soon enough, though, Adams reminds us that however pretty Virginia might be in February, “at no other season is there so much [guile].… Wealth, office, power are at auction. Who bids highest? Who hates with most venom? Who intrigues with most skill? Who has done the dirtiest, the meanest, the darkest, and the most, political work?” 
I won’t try to convince you that this is proof that Adams is an upbeat guy because he can appreciate D.C. in spring just like you and I can. But I do think the scene exists because Adams wants to remind us that he’s operating with a moral compass—by bringing his characters out into the outdoors, he highlights the immorality of what’s going on back in the capitol, and frames the Ratcliffe’s venality as not just as a matter of breaking the law but as a kind of crime against nature.
Madeleine herself exemplifies this kind of push-and-pull, trapped as she is between a culture of corruption and her own better nature. About midway through the novel she makes a crucial observation:
Underneath the scum floating on the surface of politics, Madeleine felt that there was a sort of healthy ocean current of honest purpose, which swept the scum before it, and kept the mass pure. 
Of course, later in the novel she’ll make a discovery about Ratcliffe that’s proof that the place is just scummed up again. But I think the fact that she makes that discovery is part of Adams’ point: D.C. is not in a downward spiral so much as a state of constant flux, an ugly but essential process of scumming and de-scumming. For all the criticism people make about reformers throughout the book, nobody suggests that the reformers’ instinct will ever be absent in the capitol.
And that’s the root of Madeleine’s heroism: Adams brings her to the very edge of the corruption she observes, but never lets her fall off the cliff. That feeling is never more clear to me than in the moments after Ratcliffe delivers what may be the most cynical and calculating marriage proposal in all of literature. She’s “fitted better than any woman I ever saw, for public duties,” he tells her. “Your place is there. You belong among those who exercise an influence beyond their time.”  Setting aside her eventual decision (and we’ll get to that when we talk about the book’s climax, I suspect), Madeleine is well aware of what she’s getting sucked into, and the dangers inherent in it. Adams describes the question being “presented to her face like a pistol.”
So there’s your bright side, though I admit it’s pretty dim: In Madeleine we’re rooting for an uncalculating intelligence and (to use a word that wasn’t in use in Adams’ time) self-actualization. She’s our hero because, unlike so many around her, she “dissected her own feelings and was always wondering whether they were real or not.” 
But we’ve barely gotten past the three characters at the core of the plot. What did you make of some of others swimming around the narrative, like Madeleine’s sister, Sybil, or Lords Dunbeg and Skye, or Victoria Dare, or Hartbeest Schneidekoupon? What role are they playing? Comic relief? Different degrees of striving in a status-obsessed city?