“Jungs! Opfert euch nicht! Der krieg ist doch scheiße, Hitler ist ein idiot! (message in a pro-allied propaganda broadcast) Translation: Boy! Do not sacrifice yourself! The war is but shit, Hitler is an idiot!”
Marlene Dietrich: Life and Legend https://books.google.com/books?id=MahIKu7q9X0C&printsec=frontcover&dq=Marlene+Dietrich:+Life+and+Legend&hl=en&sa=X&ved=0ahUKEwj-8OTo5P3YAhUMIcAKHbcdBp4Q6AEIKTAA#v=onepage&q&f=false
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Marlene Dietrich 28
German-American actress and singer 1901–1992Related quotes

Quoted in A. J. Sylvester's diary entry (26 November 1941), Colin Cross (ed.), Life with Lloyd George. The Diary of A. J. Sylvester 1931-45 (London: Macmillan, 1975), pp. 296-298
Later life

“Translated After Hitler, our turn.”
Nach Hitler kommen Wir.
Ernst Thälmann (1931), cited in: Michelle Goldberg. " After Trump, Our Turn! http://www.slate.com/blogs/xx_factor/2016/03/29/susan_sarandon_is_perfect_spokeswoman_for_neverhillary.html" at slate.com, March 29, 2016.
Quote is about Thälmann's refusal to oppose the Nazis in the 1932 German election helped bring them to power. It was quoted by Goldberg (2016) as historical precedent for leftists refusing to oppose Donald Trump as US President.
The English quote is mentioned in over 30 publications, mostly as a communist slogan around 1930, yet only 4 publications actually attributed the quote to Ernst Thälmann. The original quote is mentioned in numerous publications.
Disputed

Montreal Gazette, April 2003: On the Iraq war.
2003

Responding to the reporter Manuela Borges after asked about the 1964 coup d'état denial on 1 April 2014. Câmara suspende sessão sobre golpe militar após tumulto no plenário http://g1.globo.com/politica/50-anos-do-golpe-militar/noticia/2014/04/camara-suspende-sessao-sobre-golpe-militar-apos-confusao.html. G1 (1 April 2014); Jair Bolsonaro se irrita e chama jornalista de “analfabeta” e “idiota”; assista https://vejasp.abril.com.br/blog/pop/jair-bolsonaro-se-irrita-e-chama-jornalista-de-8220-analfabeta-8221-e-8220-idiota-8221-assista/. Veja SP (4 April 2014)
2014

To Leon Goldensohn, April 12, 1946, from "The Nuremberg Interviews" by Leon Goldensohn, Robert Gellately - History - 2004.
Sourced Encyclopedia of the Third Reich Louis L. Snyder

“One idiot is one idiot. Two idiots are two idiots. Ten thousand idiots are a political party.”
Was written in a slightly different way by Leo Longanesi in Italian, above form has been attributed to Kafka without evidence.
Misattributed
Source: One Idiot Is One Idiot. Two Idiots Are Two Idiots. Ten Thousand Idiots Are a Political Party, Quote Investigator, 2021-10-08 https://quoteinvestigator.com/2021/10/08/idiots/,

“Like all boys my age, I was an idiot when it came to women.”
Source: The Name of the Wind (2007), Chapter 62, “Leaves” (p. 465)