I'm not so sure you're right on the demographics there.....huge swathes of 'well meaning Guardian readers'in the likes of Oxfordshire, and even 'normal' (as opposed to the raging fascist wing) Tories aren't necessarily comfortable with the 'culture wars' tactics and leap to the hard-right.
I live on the one road into Portland Port (Bibby Stockholm) and the most evil, nasty, racist sh1t you hear is invariably heard from working class voices.
These dog whistles aren't to entice the blue wall, but the less intelligent voters within red wall/working class areas that are incapable of applying logic/critical thinking/2nd and 3rd order evaluation to to messages that appeal to their baser, xenophobic fears. These are the ones that voted Tory last time, and the party knows that they're the only ones that can possibly stop them being annihilated at the next election (unless something significantly happens between now and then.