Here are a few additional reflections on the resignation of Amber Rudd.
First, there is little doubt that this is a resignation that has probably saved her career rather than ended it.
In the face of mounting evidence that she had not till recently been sufficiently on top of the immigration brief, she jumped rather than being pushed by Theresa May - who felt that, for now at least, the government and herself as PM would have been better served by Rudd clinging on.
But there’s the rub. Rudd would have been clinging on, given - as I said yesterday - there was too much accumulating evidence that she should have known of the existence of targets for the expulsion of migrants.
Since the real running sore was the appalling systematic mistreatment of the Windrush migrants and their children, Rudd was probably fatally wounded.
If in Thursday’s local elections the Tories’ garnered even fewer votes from ethnic minorities than usual, May would then have presumably delivered the coup de grace to Rudd, to save herself.
Better therefore for Rudd to retreat to the backbenches, and prepare a few speeches for the looming post-Brexit battle to lead the Tory party.
Of course the departure does not clear up the mess that is the UK’s immigration policy.
And it leaves unanswered two big questions.
Rudd’s reasonable explanation for why she was behind the curve on immigration is that she was applying herself principally to the growing, real and present danger from terrorism, cyberwarfare and violent crime.
But that begs the question whether any Home Secretary is capable of keeping us safe and also simultaneously formulating and executing a sensitive but effective immigration policy.
That might have been possible when the world was less fraught with lethal threats, and immigration was not the single most contentious and important domestic issue.
Perhaps no longer.
Rudd’s failure may show that the home office is in fact two departments in one - and it should therefore be split in two.
Second, it remains an utter mystery why Rudd was so poorly advised by her officials on whether there were immigration targets.
Was this incompetence on their part, miscommunication or even maliciousness?
Her officials were not responsible for Rudd’s demise. But they did not help to save her.
My tip is that Sajid Javid who has replaced her - should take the job with trepidation.