If you say that someone such as a politician is demagogic, you are criticizing them because you think they try to win people's support by appealing to their emotions rather than using reasonable arguments.
[formal, disapproval]
...a demagogic populist.
demagogic in British English
(ˌdɛməˈɡɒɡɪk) or demagogical
adjective
of, characteristic of, relating to, or resembling a demagogue
Derived forms
demagogically (ˌdemaˈgogically)
adverb
demagogic in American English
(ˌdɛməˈgɑdʒɪk; ˌdɛməˈgɑgɪk; ˌdɛməˈgoʊdʒɪk)
adjective
of, like, or characteristic of a demagogue or demagogy