The ambitious young men sat for hours at a restaurant here to map out plans for a business venture that could make them millions. In a group that included three Jamaican entrepreneurs, one participant seemed out of place - a 27-year-old former U.S. Supreme Court law clerk of Cuban descent who was visiting from Washington. Ted Cruz had been invited by his roommate from Princeton and Harvard Law, David Panton, who was eager for the group to win the rights to manage a new Caribbean-focused investment enterprise launched by one of the island's most prominent executives. The idea was modeled...