I taught dh the word "gaslight" a few years ago, as he hadn't come across it, so I needed to explain what itmeant.
On that occasion, it was to do with describing what happens in domestic abuse.
He now uses the word correctly regularly to describe how BJ is treating his audience - whether that be the public, the press, Parliament.... 
Isn't it an indictment that the UK's PM not only gaslights the country regularly but gets away with it
- but hopefully, for the sake of democracy in the UK as well as its global reputation, his days are now numbered.