– Ward Cleaver had it all — until he didn’t. In the course of one fateful week, he lost his job, discovered his wife’s affair with the milkman and learned he had terminal lung cancer. Reeling from the tragic chain of events, Ward hit the brandy bottle. Hard. He began selling doobie to the neighborhood kids. Bundles of cash were found stashed under the lid of the BBQ grill. And then, one day, Eddie Haskell went missing. ...

Pitching a dark version of “Leave It to Beaver” would have been unthinkable a decade ago. But in the contemporary world of cable, where viewers are encouraged to root for serial killers, coldhearted admen, bloodthirsty bikers or meth-dealing teachers — as in “Breaking Bad,” which begins its final run Sunday — this is practically a no-brainer.

“I think we like to see somebody portray the worst in us that we’ve either felt or wanted to express. It’s kind of liberating,” said Nelson McCormack, a veteran TV director whose credits include “Boss,” a series about a corrupted politician. “You watch Kevin Spacey being ruthless in ‘House of Cards,’ and you think back to a situation where you wanted to say the exact same thing with that kind of elegance and prowess.”

Rooting for the bad guy is nothing new. Think: Warner Bros.’ 1930s gangster flicks, or even William Shakespeare’s Lady Macbeth.

Now it’s TV’s turn.

“It’s just a younger medium,” said Patty Jenkins, whose credits include the feature film “Monster” and the Emmy-winning pilot of “The Killing.” “With all these art forms, you start off with a juggling street performer who has to work his way into the circus tent. Movies always had a captive audience, so they were able to do deeper, more complex things.

“Television was always about ‘Look at me now! Look at me now! Now go away!’ That’s starting to change.”

Turning Mr. Chips into Scarface

Nowhere is that more evident than in “Breaking Bad,” which airs the first of its eight final episodes Sunday.

In 2008, creator Vince Gilligan introduced us to Walter White, a high school chemistry teacher saddled with his son’s tuition fees, dashed career opportunities and a prognosis of terminal cancer. He impulsively decides to dive into the drug business with a lackluster former student.

Over five seasons, actor Bryan Cranston — once best known as the eternally moronic father on “Malcolm in the Middle” — has steadily transmuted White into one of the cruelest characters in TV history, a guy who’s so despicable he’d poison an innocent child to set up an adversary.

“What attracted me was the notion of trying to take a serialized television series and change this character in a way that has never been done before,” said Cranston, who has won three Emmys for the role. “I was aghast by that.”

Gilligan’s stated goal: To take Mr. Chips and turn him into Scarface, with the audience dropping their sympathy for White along the way.

But something unexpected happened. Fans have been reluctant to let go, sticking by their hero’s side even if it means being dragged into hell. The pull is so strong that White’s wife, Skylar, has been hissed at on social media, even though she was initially painted as the series’ moral center.

“She was the one who most consistently said, ‘You can’t just do these things and not have consequences,’ ” said Anna Gunn, who recently picked up an Emmy nomination for her role as Skylar. “And so she became kind of a villain to people who really, really identified with Walt and were behind him and were rooting for him. If the audience really sympathized greatly with her and sided with her, then you would have lost your sympathy for Walt and then the show, I think, would have been thrown off balance.”

Bad boys are more fun

The descent into darkness has great appeal for both the writers and actors, for obvious reasons. It’s always more fun to hang with the bad guy.

Cranston has had the rare, rich opportunity to dig into a character who builds a stronger shell as the series progresses.

“When we started, he was callused over,” Cranston said. “His emotions were callused over by the depression” over his dead-end career. “Receiving news of his imminent demise allowed that volcano of emotions to erupt. And when it did, he wasn’t prepared. He wasn’t accustomed to knowing where to put his emotions and how to compartmentalize it, and it just spewed over everyone, and it got messy.”

Kurt Sutter, who created the bloody biker saga “Sons of Anarchy,” believes audiences are becoming more sophisticated and crave complicated stories and a level of violence that makes them uncomfortable.

“Because of that, I get to tell the stories that I feel I want to tell and do well,” said Sutter, who avoids watching “Breaking Bad” because it’s “too close” in tone to his drama. “It’s great there’s an appetite for that. At some point, there may be not be.”

Some cable executives are already backing away from the ledge.

“I can’t imagine a protagonist darker than Walter White,” said FX Network president John Landgraf. “The nuclear arms race for darkness is over.”

Showtime Network president David Nivens said one reason he picked up “Ray Donovan,” a new summer series starring Liev Schreiber as an L.A. “fixer,” is that the title character is more of a “guy in the middle” than White, serial killer Dexter Morgan or gangster Tony Soprano.

“I sort of felt it was necessary to have a little bit of a correction of the pendulum swing back to the middle,” he said. “I don’t think you can keep going further left of what Bryan Cranston is doing on ‘Breaking Bad.’ I’m sure somebody will figure it out. Maybe I’ll figure it out.”