Bernays defined propaganda as the “conscious and intelligent manipulation of the organized habits and opinions of the masses”. People don’t always realise that they are being manipulated; they can be persuaded to support people and policies that are not necessarily working in their best interests.
One propaganda technique is the endless repetition of snappy slogans; for example “take back control” in the campaign for Brexit, and the slogans used by Donald Trump in the 2016 American presidential election: “drain the swamp”, “build a great wall” and “crooked Hillary Clinton”. These slogans have to be endlessly repeated, for maximum effect, but they risk trivialising political debate – as pointed out in a Guardian article: ‘Strong and stable leadership!’ Could Theresa May’s rhetorical carpet-bombing backfire?.
Slogans are crude (but effective). The Institute for Propaganda Analysis has published a paper, Propaganda Techniques, which describes several other ways of exerting influence – including making false connections, being selective about the truth and creating fear. Politicians can use any of these techniques, and they can personally use the Internet to continuously reinforce their messages – with a stream of tweets, for example (18.104.22.168).
The other three clips come from Donald Trump’s successful 2016 campaign to become the American President; all three were repeated many times and also appeared in his speech in Sarasota at the end of his campaign, which was available in March 2017 at https://www.c-span.org/video/?418206-1/donald-trump-campaigns-sarasota-florida.