From Merriam-Webster, a 'Demagogue' is "a leader who makes use of popular prejudices and false claims and promises in order to gain power" and/or "a leader championing the cause of the common people in ancient times".
Wikipedia has a more in-depth look into the word 'Demagogy'.
"Demagogy refers to a political strategy for gaining political power by appealing to the popular prejudices, emotions, fears and expectations of the public — typically via impassioned rhetoric and propaganda, and often using nationalist or populist themes."
Weapons of mass manipulation
1 day ago