Robert L. F. Sikes, 88, who served for 38 years in Congress and was nicknamed the "He coon" because of his raccoon-like tenacity, died Wednesday of Alzheimer's disease in Crestview, Fla. The Democrat was elected to Congress in 1940. He was credited with building his district into an arsenal with 14 military nTC bases at the height of his career in the mid-1960s.