They are the children of the Cuban exiles who formed modern Miami, and they are among those who will shape the future of the United States. There also is the possibility they will play leading roles in a future Cuba. But regardless of how things shake out in their ancestral home, Garcia and Ugalde are a force to be reckoned with here and now. Garcia, as many in both Miami and Washington, D.C., are aware, is the new executive director and long-time spokesman for the Cuban American National Foundation. He has been active in politics for a good part of his 37 years, and no doubt his political star will continue to ascend. Ugalde, Garcia's wife of nine years, has been less publicly visible though no less accomplished. A magna cum laude graduate of Harvard with a law degree from the University of Miami, she served for six years as associate general counsel for UM. This past February she moved into the spotlight when she was named senior advisor to Donna Shalala, the new University of Miami president and former secretary of U.S. Health and Human Services in the Clinton administration.