The Prime Minister’s safest choice to replace Amber Rudd would have been Karen Bradley – another Remainer, another woman, and a May loyalist. As a former Home Office Minister and a Prime Ministerial protege, Bradley would in all likelihood have continued the net migration policy, and guarded her boss’s record over Windrush, illegal immigration, and Home Office management during the Coalition years and the run-up to the EU referendum.

Sajid Javid is also a Remainer – but there the resemblance ends. His approach to migration is instinctively liberal – or, to put it more accurately, business-friendly. He was part of the loose alliance of Ministers who, when George Osborne was Chancellor, wanted students to be taken out of the immigration figures.

Furthermore, he is not a May partisan. Javid is a former Osborne protege, was a supporter of Stephen Crabb’s leadership bid, and was not a shoo-in to be kept on by her in Cabinet after she became Prime Minister. But Downing Street would have been nervous of sacking the only Muslim in Cabinet, and so Javid was sent to housing, in the hope that his brains and energy would make an impact. As indeed they did: he was soon clashing with May over policy; he wanted a less cautious approach. After last summer’s election, he became bolder and more outspoken – leading the charge in Cabinet, according to Tim Shipman, for the defenestration of Nick Timothy and Fiona Hill as chiefs of staff.

His appointment can thus only be read as a sign of Prime Ministerial weakness rather than strength. Javid will have clocked the central facts of Rudd’s tenure at the Home Office: that she favoured a more liberal immigration policy, and was therefore at odds with Theresa May’s legacy…but loyally shouldered the burden and carried it on, while making it known now and again that she didn’t really want to. This position was inherently problematic. It was ultimately made fatal by Rudd’s lack of strategic direction and attention to detail. We noted the warning signs over knife crime earlier this month. They flared up again over the Windrush children and illegal migrants – so different on paper; so linked in Home Office practice.

Though Javid will need to play himself in to his new brief, he won’t want to hang around on immigration policy. Rudd delayed advancing one for post-Brexit Britain because of pressure from Downing Street. Her replacement is more likely to take the bull by the horns – even if it means making waves with some Brexiteers by promising special treatment for EU27 nationals in the event of a trade deal (and other countries with which we make such arrangements). But what Brexit supporters lose on the swings they could gain on the roundabouts. The new Home Secretary is not an enthusiast for the customs partnership, recognising a problematic scheme when he sees one. His stance on leaving the EU seems to be: I wasn’t in favour of it – but now we’re going to do it, let’s do it properly.

Much will be written about the creation of Britain’s first-ever Muslim Home Secretary. As it happens, Javid is a bit of semi-detached Muslim. He tells friends that, while he isn’t a regular worshipper, being Muslim is part of his identity. Like several Muslim Tory MPs, he has married out of the religion. But he none the less has an insight into Islamist extremism which makes him take a flinty position on it – honed at HCLG, where he had the integration brief, and was an enthusiast for Louise Casey’s integrationalist ideas.

There is a view that Javid isnt really a politician at all – that he is essentially a banker who, though very able, lacks that indefinable, essential political touch. His promotion, and his fierce commitment to building more homes in his previous brief, should put pay to all that. He has gone down the fast track, been derailed – and pushed and shoved his way back. The only advice we offer him today is: you have one of the better teams of special advisers. Take it with you to the Home Office.

This is a paradox of an appointment. The rational banker has turned emotive operator – as he proved over the weekend by draping himself in the mantle of Windrush. The protege of Osborne has been promoted by May. The man who wants to be Chancellor has got a great office of state – but a different one. A Home Secretary with liberal inclinations on migration must now square suspicious voters – most of whom take an uncompromising view on illegal immigration and want a more restrictive policy. Conceived in political weakess, the move is somehow bold. And it won’t do any harm at all during this run-up to Thursday’s local elections.

But one point is clear already: the curtain is coming down on the May era at the Home Office. And, inevitably, that leadership talk about Javid will soon get going again.