brainwash
verb to convince someone systematically and in a manipulative manner that something they do not believe is true. Although the term was coined to describe the actions of authoritarian, Soviet-bloc regimes, probably the most famous use of 'brainwash' in the US was by George Romney, candidate for the Republican presidential nomination in 1968, who claimed that he had been brainwashed to support the US war against Vietnam
US, 1951