The Tories did best in constituencies that voted heavily for Brexit: in six of their eight new English seats the Leave vote was over 60%.
But Brexit hurt the party in other places.
Excluding Scotland, there is a strong correlation between swings from the Tories to Labour and the vote in the EU referendum.
By our seat-by-seat analysis, Brexit was responsible for about half of the national swing from the Tories to Labour.
Labour said as little as possible about the subject, allowing it to attract voters from both sides of the referendum divide.
It gained 18 seats in lukewarm Leave constituencies and 13 in areas that voted Remain.
All told, of the 28 seats the Tories lost to Labour, perhaps 17 can be explained by some combination of higher turnout, large populations of young and educated voters, and opposition to a hard Brexit.
That leaves 11 seats dotted around England where those elements were not sufficient to explain the result.
Seven years of austerity under the Tories are likely to have counted; so is Theresa May's dour campaign, which failed to learn from the Scottish independence referendum of 2014 that positive messages matter.
It was nearly very different.
The Tories lost four seats by 30 votes or fewer.
The current distribution of votes means that the number of seats won is more “elastic” relative to vote share than in the past, Mr Curtice notes.
A 2.5 percentage-point swing from Labour to the Tories would have won them 29 more seats, giving them a 51-seat working majority—and turning the narrative of Tory disaster into one of triumph.