"I am mad. I'm always losing things and hiding things. And I can never find them. I don't know where I've put them."
--Paula Anton (Gaslight)
In the classic 1944 film, Gaslight, Gregory Anton (played by Charles Boyer) tries to get his recent bride Paula (played by Ingrid Bergman) to believe that her perception of reality is wrong and that she is going mad. For example, Gregory moves things in the house and then claims that Paula did it even though she has no recollection of it. He also isolates Paula so that she has little contact with people outside of the house.
The film's title refers to the gaslights that illuminate the couple's old London townhouse previously owned by Paula's rich aunt. Paula occasionally hears footsteps up in the attic, the door to which is locked. Whenever she hears the footsteps, the gaslights dim. Whenever Paula tells Gregory about this, he tells her that she must be imagining it.
Over time, the reinforcement that her perceptions of reality are wrong coupled with little exposure to outsiders leads Paula to doubt her sanity.
It turns out that Gregory had murdered his wife's rich aunt before he and Paula were married, and is snooping around the attic to look for the aunt's valuable jewels that he is convinced are there. Whenever he climbs into the attic thru a roof-side window and turns on the attic lights, the gaslights dim on the floors below.
Ultimately, Scotland Yard investigator Brian Cameron (played by Joseph Cotton) intervenes. He pegs Gregory for the murder/thief that he is, and sneaks into the house one night to see Paula while Gregory is up in the attic. He demonstrates the cause and effect of the footstep/gaslight phenomenon which helps restore Paula's sanity. Cameron, of course, subsequently gets his man--and perhaps, we are lead to believe, the girl as well.
This article describes the psychological tactic of 'gaslighting' as practiced by the political Left. Gaslighting is defined as a form of mental and emotional abuse in which a domineering person denies the memories and perceptions of an intended victim until the victim begins to doubt his perception of reality. The article suggests that the Left's version of gaslighting is to push a false view of reality and then try to convince mainstream Americans that their views are extreme and not grounded in reality.
Benghazi, Obamacare, racism, global warming, Islamophobia, Trump's election, Russian hacking. Most if not all major narratives chanted by the Left contain gaslighting features.
Of course, the Left owns no monopoly on gaslighting methodology. For example, the national security state construct coddled by Neocons is pushed by a great deal of gaslighting as well.
How to counter gaslighting? Develop capacity for processing information and be confident in your ability to reason. Shun dependence on strong, mesmerizing personalities who can sway your thinking. Avoid excessive socializing with narrow groups so that you can grow your mind, and develop and test plausible rival hypotheses.
Gaslighting can be seen as a form of propaganda. Strengthen your mind to avoid succumbing to narrative-driven propaganda that gaslighting promotes.