Sometimes it's best to just agree [whilst trying not to sound too condescending]
rather than challenge the personal reality a deluded person has created for him/her self...

That's what I've learnt from experts how to deal with my old mum's persistent irrational behaviour and diminishing grasp on truth...

So maybe the best way to cope with die hard tories and their shill supporters,
is to calmly repeat "yes dear, if you say so..."...????