It is said that Franklin D. Roosevelt encouraged Chaplin to make the The Great Dictator. Indeed, around the time the film was made, the two men shared political views on a lot of things. When Churchill and FDR saw a pre-release private screening of the film, they liked it. (Incidentally, Chamberlain had vowed to ban it in England for fear of angering the actual dictator.) FDR even invited Chaplin to read this very speech on his inauguration in 1941.

Ironically, this is the film that made Americans turn against him. Later that year, he was subpoenaed by a congressional committee investigating pro-war propaganda (this was a few months before the US entered the war.)

In the following years, Chaplin was extremely vilified by the Americans mainly for his pro-Soviet and communist views (or rather, for his refusal to be anti-Communist). This led to politically-motivated prosecutions, and culminated in him being exiled from the US when the president Harry Truman(!) canceled his re-entry permit while away on family vacation. (Chaplin was never an American citizen, despite living in the country for over 40 years.)

There’s a recent good book review summarizing this: https://www.newyorker.com/magazine/2023/11/20/charlie-chapli...