In 1998, the professional moral scold William Bennett published a book titled “The Death of Outrage: Bill Clinton and the Assault on American Ideals.” In it, Bennett described blasé attitudes toward presidential adultery as corrosive. Clinton’s promiscuity, he argued, implicated his fitness for governing: “Chronic indiscipline, compulsion, exploitation, the easy betrayal of vows, all suggest something wrong at a deep level — something habitual and beyond control,” he wrote.

I was reminded of Bennett’s words by David Friend’s fascinating recent book, “The Naughty Nineties: The Triumph of the American Libido,” about the sexual scandals and cultural upheavals of that decade. In retrospect, the dynamics of the Clinton-era culture wars seem blissfully simple, pitting a sexually libertarian left against an aggressively prudish right. It is a cosmic irony that, 20 years later, it is conservatives who’ve finally killed off the last remaining unspoken rules about presidential sexual ethics.

On Friday, The Wall Street Journal reported that, a month before the 2016 election, Donald Trump’s lawyer Michael Cohen arranged a $130,000 payout to the porn star Stephanie Clifford, known by the stage name Stormy Daniels, to stop her from discussing a 2006 dalliance with Trump. The New York Times added new details. The Daily Beast then reported that another porn actress, Jessica Drake, who had accused Trump of offering her $10,000 for sex, signed a nondisclosure agreement barring her from talking about the president.

In any other administration, evidence that the president paid hush money to the star of “Good Will Humping” during the election would be a scandal. In this one it has, so far, elicited a collective shrug.