Britain is becoming ever more diverse, urban and university-educated. May has put the Tories on the wrong side of that shift.
Her strategy was to win UKIP and socially conservative Labour votes on the assumption that liberal Torydom could be taken for granted.
So she ran a gloomy, hyper-nationalist, conspicuously anti-metropolitan campaign inviting voters to despise foreigners & internationalists.
This seemed unappealing and (to coin a phrase) *nasty* to many swing voters, other liberals, non-white Tories and young Britons.
Combined with Corbyn's excellent campaign, it reapplied the glue affixing working-class Labourites to the party's metropolitan-liberal base.
So Labour did well in its strongholds, but also Londonish swing seats: uni towns, worldly service centres, other big-cities & their suburbs.
The Conservative problem now is that these places look like Britain's future, for reasons I explain in this paper: policy-network.net/publications/4…
In short, May's Tories seem to dislike modern Britain. And guess what?! Allying with the anti-gay, quasi-theocrats of the DUP does not help.
Modern Britain will have views on that. And who knows? Perhaps modern Britain will even vote in a party keen on the country it seeks to run.
And perhaps that party will be Labour. But if you are a Tory and want to be that party, listen up and listen good...
There is an alternative: in Scotland, Ruth Davidson is pioneering a modern, liberal Toryism at ease in its skin and in its country.
This Toryism is for a soft Brexit within the single market. It rejects DUP's bible-bashing bunkum. It is humorous & human. It is moderate.
Conservatives boast that their centuries-old secret is their endless adaptability. OK, prove it. Grow up. Replace May with Davidson.
Persuade an old duffer with a safe seat to step down and let Davidson into Parliament. Then make her leader.
That's just my advice. But the fact remains that Britain is changing. Its liberal, diverse urbanites are marching into marginal territory.