Third time... unlucky?

You would have thought they would have noticed a pattern by this time.

I wonder if he will still, behind the scenes, be a dominant force in running the government? McSweeney is his protegee. Starmer is an empty vessel. Can't help but wonder...

Most likely. Mandelson is almost certainly Starmer's boss and is channelling influence as he and Blair have always done. But why did Mandelson have to become ambassador the moment Trump took power?

For the status, probably.