Damian Lewis as billionaire hedge fund manager Bobby “Axe” Axelrod in “Billions.” (Jeff Neumann/Showtime)

The first season of Showtime’s “Billions” ends with the show’s two larger-than-life adversaries standing in the wreckage they’ve made of their lives. When two extraordinarily powerful men are pitted against each other, the doctrine of “mutual assured destruction” is supposed to act as a deterrent, preventing them from considering the nuclear option. And yet here they are — U.S. Attorney Chuck Rhoades (Paul Giamatti) and billionaire hedge fund manager Bobby “Axe” Axelrod (Damian Lewis) — in the bomb crater of Axe Capital, a once-sleek monument to unfettered capitalism, now reduced to a ravaged sales floor and wires hanging from the ceiling.

In his effort to bring Axe to justice for his relentless abuse of the financial system, Chuck has damaged his reputation and lost his marriage to Wendy (Maggie Siff), a corporate psychiatrist. In defending his business, Axe has also damaged his reputation and lost his relationship with Wendy, who happened to serve as his in-house performance coach for 15 years. The key insight to “Billions” — and a major source of the outrageous week-to-week excesses that make it so entertaining — is that Axe and Chuck will never stop fighting, no matter how much damage they do to themselves or the people they love. Their inflated egos cannot be punctured by humility.

“Billions” returns for a second season Sunday, to a world in which another New York billionaire, Donald Trump, has assumed the presidency. Though showrunners Brian Koppelman and David Levien have incorporated real-world developments in their previous work — their 2009 film “The Girlfriend Experience” is layered with chatter about the Great Recession — the name “Donald Trump” does not come up until the fourth episode. And even then, Koppelman and Levien are not interested in editorializing. They just know the type.

Showrunners Brian Koppelman and David Levien speak at the TCA Winter Press Tour in Pasadena, Calif. on Jan. 9. (Eric Charbonneau/AP Invision for Showtime)

“We don’t try to track the headlines,” Levien said. “We try to establish a veracity in the behavior based on what we’ve seen. If there are events in the show that actually echo what’s going on in current events, that’s usually coincidental. We just try to get to the essence of what makes these people create these events.”

“Part of what we wanted to do,” Koppelman said, “was look at the true nature of access, influence and the power of billionaires and high-level federal prosecutors. When you think about this unfettered power and control that billionaires can have — that rapacious need really sets the bar. It’s a show about this outsized ambition, the need to have what you want to have, and the ability to get it, and whether that’s a good or bad thing.”

One of the most compelling aspects of “Billions” is that it is as much a reflection on how the public perceives the rich and powerful as it is a condemnation of the rich and powerful. In the second season, Christopher Denham joins the cast as Oliver Dake, a special investigator assigned to examine Chuck’s serious ethical lapses and prosecutorial overreach in his case against Axe — all of which we, the viewer, have witnessed, on top of the lies and betrayal in his marriage. And yet it is Oliver who reads as the villain in this scenario, not Chuck. That says something about our attraction to charismatic antiheroes.

Paul Giamatti as U.S. Attorney Chuck Rhoades. (Jeff Neumann/Showtime)

“From the beginning, we’ve wanted to play with allegiances and who people root for,” Levien says, “in the hope that people come to a realization, like ‘Why am I rooting against the guy who’s actually unconflicted and doing good?’ ”

For Koppelman, one of the motivating factors of the show is to understand how money and success forgive affronts to decency — a phenomenon that might explain Trump but is certainly not limited to him.

“We’re really interested in figuring out why people give a huge pass, sometimes, to incredibly successful people as long as these people are, in fact, successful,” he says. “We were and still are compelled to examine why grabbing power and influence is a stand-in for being a quality person in the minds of many people.”

The second season also introduces a unique challenge to that power in Taylor Mason (Asia Kate Dillon), a gender nonconforming character who starts as an intern at Axe Capital and whose analytical brilliance proves an indispensable asset. Operating under the pronouns “they,” “theirs,” and “them,” rather than he-or-she binaries, Taylor shakes up a business culture that’s hypermasculine and notoriously resistant to change. But in an office often playfully likened to a zoo, tension over Taylor’s presence is a certainty.

Asia Kate Dillon as Taylor Mason. (Jeff Neumann/Showtime)

“We wanted somebody as smart as Bobby Axelrod in the room,” Koppelman says. “As we started to think about the character, we realized that we had an opportunity to introduce into Axe Capital somebody who looks quite different — who would cause people to, in a supposed meritocracy, react in a certain way. At the same time, we didn’t make it a message thing. We put this person into this world. They have these incredible skills. They also happen to be gender non-binary. We let that situation play itself out.”

For Koppelman and Levien, “Billions” continues an almost two-decade-long collaboration about the rogues in American culture, those men and women who make their money playing the angles. This includes the poker sharps of “Rounders” and “Runner Runner,” the thieves and casino brass of “Ocean’s Thirteen,” the high-end prostitute in “The Girlfriend Experience,” and Michael Douglas’s car salesman in “Solitary Man.” “Billions” deals with dirty dealers on a much larger scale, as the first-time showrunners have an expansive terrain of 12-episode seasons. But they’ve approached “Billions” with the same journalistic rigor as their past projects, drawing on conversations with hedge-funders who, like their other characters, exist outside the normal channels of society.

“We made studies of how these people in these positions comport themselves,” Koppelman says. “More than that, we thought about what was going on in their internal lives and the way people looked at them.”

“I don’t think the world has made liars out of us,” he adds. “Though our show is a lot funnier than Trump.”