Average swing in Con held seats - 4.7% (England only) Average swing in Lab held seats - 4.5% Average swing in seats changing hands - 8.3% - that must be worth at least 15 English seats.
So a particular demographic or a message that struck a chord with those particular voters?
I wonder how many of the Con gains were actually target seats.
You did ask...I did a cluster analysis for English seats (bar Buckingham and Chorley) - Brexit vote (Nigel Marriott's estimates) v Wealth/Deprivation v % Muslims v population density. Some identifiable trends:-