If only they could track down the person who was Britain’s  Home Secretary ‎from 2010 to 2016. Then we might get some answers about what on earth he or she thought they were doing allowing an immigration policy to run so badly out of control that citizens invited here after the Second World War from the Caribbean can be threatened with deportation.

But I fear we’ll never find out who was Home Secretary in that critical period. The mystery is beyond unravelling.

We know who is Home Secretary now, that is Amber Rudd, who is getting it in the neck from furious MPs of all parties. Rudd is the hitherto capable ally of Theresa May. That is Theresa May, former… ‎of course… former Home Secretary! From 2010 to 2016.

At that time it was fashionable to say that May delivered. She could be difficult, said colleagues, but there was a solid, unflashy and reliable operator at work who could when she needed to stare down Cameron and Osborne. It is from that period that the erroneous theory of May’s inscrutibility and alleged wisdom dates. She says so little. She appears enigmatic. She must have it all worked out. What a player. So calm. She says so little. And so on.

On the basis of that misunderstanding (there must be something really brilliant going on behind the stare) and thanks to the country needing saving from Andrea Leadsom, May became Prime Minister. And then, oh dear. It became apparent that there was no.

May does, though, guard the reputation of her time at the Home Office jealously. Ministers are wary of doing anything that implies a criticism of May’s tenure. Tough and basic question thus go unasked. It is very unhealthy, just as it was unhealthy in the Gordon Brown era that criticism of his time as Chancellor was forbidden in Labour and Whitehall. Big mistakes were missed.

The effects in that case were economic. This May farce turns out to have human consequences for those Windrush Britons fearful for their futures.

We are forever hearing that Brexiteers are the ghastly nationalists always banging on about immigration, heartless and cruel. Rudd and May were Remainers, yet this dreadful policy happened on their watch.