Guatemala is at least a possibility. To quote (with some modifications) an old soc.history.what-if post of mine:
"In all fairness to those who were worried about Communist influence in Guatemala, it must be said that the power of the Guatemalan Communist Party (PGT or Guatemalan Labor Party as it called itself) cannot be measured by its small membership and minimal representation in Congress. What most worried anti-communists was the influence on President Arbenz of Communist leaders like Jose Manuel Fortuny
https://en.wikipedia.org/wiki/José_Manuel_Fortuny and especially of Victor Manuel Gutierrez,
https://en.wikipedia.org/wiki/Víctor_Manuel_Gutiérrez head of the CGTG (General Confederation of Guatemalan Workers) which controlled the urban-based unions. Without a doubt Arbenz, though not himself a Communist, admired Gutierrez and often turned to him for advice; he later said that he thought the PGT was a more consistent supporter of his reforms than the more moderate parties in his coalition. Communist influence was real and substantial. But this is not the same thing as Communist *domination* which never occurred in Guatemala.
"Furthermore, there was a lot of anger in the US over Guatemala being the only country in the Americas whose Congress held a memorial service for Joseph Stalin. Now this does not make Arbenz a Communist any more than De Valera was a Nazi for spending some time with the German Minister offering condolences on Hitler's death. In each case, the motive was to prove that though small, Ireland (or Guatemala) was truly independent (whether of Great Britain in the Second World War or of the US in the Cold War). But in each case, the method chosen--honoring a mass murderer --was IMO morally wretched. Needless to say, this does not justify the US intervention, any more than Churchill would have been justified in invading Eire. (It also didn't help Arbenz that he tried to smuggle arms into Guatemala from Czechoslovakia--but he felt he had no choice, since the US had prevented him from getting them from western countries. Ironically, it turned out the weapons Arbenz purchased from the Czechs were mostly obsolete or otherwise useless.)"
In short, although Arbenz as of 1954 was pink rather than red, it would not be farfetched to see him becoming a Communist if the CIA coup to oust him had failed and he was convinced that only the Soviet bloc could save Guatemala's revolution. (In OTL, he did eventually join the Communist Party while in exile in Uruguay.
https://en.wikipedia.org/wiki/Jacobo_Árbenz)