Attempting to define reality is a core feature of authoritarianism. This is what the Soviets did when they erased political dissidents from historical photos. This is what happens in George Orwell's classic novel Nineteen Eighty-Four, when a torturer holds up four fingers and delivers electric shocks until his prisoner sees five fingers as ordered. The goal is to make you question logic and reason and to sow mistrust toward exactly the people we need to rely on: our leaders, the press, experts who seek to guide public policy based on evidence, ourselves. For Trump, as with so much he does, it's about simple dominance.
-- Hillary Rodham Clinton, What Happened, p. 9