Despite the kind of publicity and hysteria usually reserved for big-budget summer films, Lena Dunham’s HBO dramedy “Girls” earned its worst premiere ratings to date with a paltry (even for “Girls”) 680,000 viewers.

By comparison, season 3 debuted to 1.1 million viewers. That’s nearly a 40% drop this year. In the all-important 18-49 age demo, “Girls” pulled only 390,000 viewers, a dip of 35%. Things are moving in the wrong direction — the season 3 premiere was a 28% improvement over the season 2 premiere.

For more context, of the 15 HBO series ranked here, “Girls” currently ranks 10th.

This is an apples-to-apples comparison. Although total viewership will increase over the course of the week through replays and HBOGo (what’s known as Live Plus 7 ratings), the numbers above all represent initial viewers. For the past 3 years, “Girls” has premiered in competition with the Golden Globes ceremony, so that wasn’t a factor in this year’s decline.

One major difference that should have increased Sunday’s ratings was the five-alarm media hoopla around the season 4 premiere. This summer Dunham was everywhere on her book tour: magazine covers, talk shows. Just a few months later she was everywhere again promoting “Girls.” Even before its broadcast, this episode garnered a frenzy of nationwide publicity all week over a raunchy sex scene everyone’s still talking about. Moreover, just before the premiere, Dunham managed to cause yet another a stir by releasing nude photos of herself.

If that wasn’t enough, for the last few months Dunham has glommed onto mainstream superstar Taylor Swift and milked that friendship for an endless supply of free publicity.

One dramatic difference between the premiere of seasons 3 and 4, however, is the controversy Dunham faced in November when it was discovered that a number of facts — in what was advertised as her non-fiction memoir — were completely made up.

Worse, those manufactured facts resulted in an innocent family man living for months under a cloud of suspicion as Dunham’s rapist. Worse still, it was revealed that Dunham remained silent even after she knew her memoir had indicted an innocent man as her rapist.

Although Dunham is considered sacred in left-wing mainstream media and entertainment circles, it was impossible to wish this story into the cornfield after Dunham’s publisher, Random House, made the dramatic move of agreeing to alter future prints of the memoir and offered to pay for the legal expenses incurred by this innocent man (Breitbart News identifies him as Barry One) while attempting to clear his name.

Dunham also claimed her rapist was a conservative Republican. The left-wing Gawker believes it has proved that a lie.

There can come a devastating moment in the life of any entertainer when something forever alters the public’s perception of you. Meg Ryan never recovered from her adulterous on-set affair with Russell Crowe. Harrison Ford never recovered after dumping his wife for a much younger woman. Burt Reynolds’ career ended after insulting his audience with “Stroker Ace.”

Dunham’s small but loyal base is obviously made up of young, left-wing feminists. She is, or at least was, their spirit guide. But they now know that when it came to an issue as important as rape, Dunham wasn’t even close to honest with them. And to stand silently by as you knowingly allow an innocent man to twist in the wind under a false rape allegation — who wouldn’t find that craven and indefensible?

Dunham led the charge of her memoir’s publicity blitz with a rape story that completely unraveled. Additionally, after shaming others into voting, it was discovered Dunham didn’t vote. There was also a controversy surrounding Dunham’s unnatural sexual fascination with her much younger sister.

Fans will put up with a lot of bad behavior until it involves lying, hypocrisy and a child. On those three points, Lena Dunham hit the trifecta and appears to have lost at least part of what was already a very small audience.

John Nolte on Twitter @NolteNC