There is a term for this conduct "McCarthyism". The tem incorporates the name of Senator Joe McCarthy who exploited fear and paranoia for political gain. . This is from Wikipedia :  "McCarthyism is the practice of making accusations of subversion or treason without proper regard for evidence.[1] It also means "the practice of making unfair allegations or using unfair investigative techniques, especially in order to restrict dissent or political criticism."[2] The term has its origins in the period in the United States known as the Second Red Scare, lasting roughly from 1950 to 1956 and characterized by heightened political repression against supposed communists, as well as a campaign spreading fear of their influence on American institutions and of espionage by Soviet agents.

Link: https://en.wikipedia.org/wiki/McCarthyism