Original sentence: The vast majority of Cubans who fled during the Mariel Boat Lift were legitimate asylum seekers.There was also an estimated 20,000 convicts, homosexuals and mentally disabled on board
Edited sentence: Although the vast majority of Cubans who fled during the Mariel Boat Lift were legitimate asylum seekers, Castro used the event as an opportunity to expel an estimated 20,000 convicts, homosexuals and mentally disabled citizens