A movie about a bunch of ruthless oligarchs who use a pretend president actor to mask themselves

Moon over Parador is a (1988) romantic comedy film, starring Richard Dreyfuss, Raul Julia and Sonia Braga. It is a remake of the 1939 film The Magnificent Fraud, based on the unpublished short story entitled "Caviare for His Excellency" by Charles G. Booth.