Others will be shocked by his sleazy, self-regarding disloyalty and apparent lack of concern for Jeffrey Epstein’s victims, but something that will puzzle people who knew Peter Mandelson is: how could he be so stupid?

Should you be thinking of stabbing a colleague in the back, and betraying your country, your government and your party – to paraphrase the prime minister – a basic precaution is not to leave an email trail. During the 2008 expenses scandal, it was the MPs who left proof of their dishonesty in emails who went to jail. I suspect many others got away with it for want of written evidence. You might think a politician so deviously clever that they call him the Prince of Darkness would know that, and not end up with police searching two of his houses.

And any sensible adult knows that lying during a job interview is not only dishonest, but can blow up in your face – yet, according to Keir Starmer, Mandelson “lied repeatedly” to secure that post as UK ambassador in Washington. Furthermore, if you are freeloading off a manipulative sleazebag, it is better not to wander about his house in your underpants, in case there are hidden cameras. And yet this highly intelligent political operator created a trove of self-incriminating evidence and left it all in the care of a convicted paedophile.

When I worked alongside Mandelson 40 years ago, he had one of the sharpest minds I have ever come across. The Labour party was still reeling from a catastrophic general election when he took over as its director of communications on his 32nd birthday. It was dominated by trade unions. It looked out of date and........

© The Guardian