RESEARCH is important when writing a blog. That’s my excuse for typing Stormy Daniels into Google and looking at her pictures.

The alleged relationship between President Trump and the woman the Guardian describes this morning as “a pornographic film actor” is knottier than a tangled sheet: she says they had an affair, he denies it.

Stormy Daniels is a brassy blonde who appears to have undergone a degree of enhancement a few inches below her sharp chin. She is a cartoonish representation of a woman, all tumbling peroxide, thrusting chest and pouty smile.

She is, in other words, just the sort of woman you imagine Donald Trump would choose for an extra-marital dalliance.

“By the president’s personal attorneys and for details on that I would refer you to them.” Er, what?

Days before the 2016 presidential election, Daniels is said to have signed a non-disclosure agreement barring her from discussing the alleged rumpy-Trumpy. She now contends that this deal is “null and void and of no consequence” because it was not personally signed by Trump.

This matter has resurfaced again after the White House mysteriously claimed that Trump won a case “in arbitration” against Daniels about their alleged affair ten years ago.

In an oddly worded announcement, press secretary Sarah Sanders appeared to confirm the existence of such a contract, saying that the case “has already been won in arbitration” – thought to refer to a cheaper option to litigation.

Then she uttered the following enigmatic words: “By the president’s personal attorneys and for details on that I would refer you to them.”

What an impenetrable sentence: its meaning as mysterious as its gnomic syntax.

For a moment there, I recalled former US defence secretary Donald Rumsfeld and his famous statement that “there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns…”

Rumsfeld was speaking about what was known about weapons of mass destruction in Iraq. He was addressing something important and much contested. Trump’s press secretary was addressing whether Trump had an affair with a porn star or not.

“Perhaps Trump isn’t so exceptional then, although it does appear that Kennedy had better taste, if nothing else”

The truth is oddly immaterial as Trump famously says whatever he likes and shouts down opponents by calling them liars.

Did he have an affair with that porn star – sorry, “actor”? Who knows, but it seems snugly within the realms of possibility. And that’s why electing someone like Trump risks all sorts being brushed under the White House carpet.

Rumsfeld was much mocked at the time for a statement that seemed designed merely to obfuscate. But in the present American political climate, his “known knows” suddenly sound like the clearest good sense.

A National Geographic feature from October 2013 reminds us that other American presidents have had affairs. The historian Robert P Watson, who has researched sexual indiscretion in the White House, numbers seven straying presidents, from Thomas Jefferson to Bill Clinton. John F Kennedy’s dalliances were the most legendary and are said to have included an affair with movie star Marilyn Monroe.

Kennedy’s friend told Kennedy’s biographer, Robert Dallek, “Jack liked girls. He was a great chaser.”

Perhaps Trump isn’t so exceptional then, although it does appear that Kennedy had better taste, if nothing else.